Stent features for collapsible prosthetic heart valves

ABSTRACT

A prosthetic heart valve includes a stent having an expanded condition and a collapsed condition. The stent includes a plurality of distal cells, a plurality of proximal cells, a plurality of support struts coupling the proximal cells to the distal cells, and at least one support post connected to a plurality of proximal cells. The proximal cells are longitudinally spaced apart from the distal cells. Various strut configurations and connections of the struts to the proximal cells and of the proximal cells to the support post improve stent flexibility and reduce stress in the valve leaflets.

The present application is a continuation of U.S. patent applicationSer. No. 13/203,627, filed on Dec. 7, 2011, which is a national phaseentry under 35 U.S.C. §371 of International Application No.PCT/US2010/000561, filed Feb. 25, 2010, published in English, whichclaims the benefit of the filing date of U.S. Provisional PatentApplication No. 61/208,834, filed Feb. 27, 2009, the disclosures ofwhich are hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present disclosure relates to prosthetic heart valves and, morespecifically, to prosthetic heart valves having a collapsible stentframe.

Current collapsible prosthetic heart valve designs are for use withinhigh-risk patients who may need a cardiac valve replacement, but who arenot appropriate candidates for conventional open-chest, open-heartsurgery. To address this problem, collapsible and re-expandableprosthetic heart valves have been developed that can be implantedtransapically or percutaneously through the arterial system. However,such collapsible valves may have important clinical issues because ofthe nature of the patient's native stenotic leaflets that may not beresected as with the standard surgical practice of today. Additionally,patients with uneven calcification, bicuspid disease, and/or aorticinsufficiency may not be treated well with the current collapsibleprosthetic valve designs. The limitation of relying on evenly calcifiedleaflets has several issues, such as: (1) perivalvular leakage (PVleak), (2) valve migration, (3) mitral valve impingement, (4) conductionsystem disruption, etc., all of which can have adverse clinicaloutcomes. To reduce these adverse events, the optimal valve would sealand anchor to the cardiac tissue adequately without the need forexcessive radial force that could harm nearby anatomy and physiology. Anoptimal solution may be to employ a stent that exerts a radial outwardforce just large enough to hold open the native stenotic/insufficientleaflets, and to use additional anchoring features more reliant onanother anchoring methodology while reducing leaflet/stent stresses.

After multiple clinical valve failures during the late 1960's and early1970's, a series of investigations on leaflet failure (e.g., dehiscenceat the commissures) and stent post flexibility began and continue to beexplored today. (Reis, R. L., et al., “The Flexible Stent: A New Conceptin the Fabrication of Tissue Heart Valve Prostheses”, The Journal ofThoracic and Cardiovascular Surgery, 683-689, 1971.) In-vitro, animal,and clinical investigations showed that “a flexible stent greatlyreduces stress on the valve,” which was as large as a 90% reduction ofthe closing stresses near the commissures when flexibility andcoaptation area were maximized.

In more recent years, several groups have shown (e.g., via numericalcomputations) the importance of stent post flexibility during openingand closing phases to reduce leaflet stress and therefore tissuefailure. (Christie, G. W., et al., “On Stress Reduction in BioprostheticValve Leaflets by the Use of a Flexible Stent,” Journal of CardiacSurgery, Vol. 6, No. 4, 476-481, 1991; Krucinski, S., et al., “NumericalSimulation of Leaflet Flexure in Bioprosthetic Valves Mounted on Rigidand Expansile Stents,” Journal of Biomechanics, Vol. 26, No. 8, 929-943,1993.) In response to several rigid Ionescu-Shiley clinical valvefailures in which the leaflets tore free at the commissures, Christie etal. (cited above) explored what would happen if a similar design wasmade with optimal flexibility. Stresses at the post tops were shown tobe five times greater than at the belly of a leaflet. Thus, to optimizethe design, the stent was made more flexible until the stresses in theleaflets were comparable to those in the leaflet belly. It was shownthat a 0.2-0.3 mm deflection was all that was needed to make asignificant reduction in stress, but that a deflection of approximately1.1 mm would reduce the stress by up to 80%. Furthermore, it wasexplained that deflection beyond 1.1 mm was not only difficult toachieve with the available material and design, but did not result inadditional stress reduction.

Krucinski et al. (also cited above) have shown that a 10% expansion (asmay be the case during the opening phase of a Nitinol stent) may reducesharp flexural stresses by up to 40% (e.g., “hooking”). This is likelydue to the stent functioning in harmony with the patient's aortic root,or in other words, the commissures of the native valve moving outwardduring systole.

Although the above analyses and data may not be directly applicable tothe collapsible valve designs detailed later in this specification, thebasic understanding and theory about how pericardial tissue leafletsinteract with a stent design as it functions are important toincorporate into any design where durability is paramount. It ispossible that with good engineering design of the post and leafletattachment, commissural dehiscence will not be a primary failuremechanism.

BRIEF SUMMARY OF THE INVENTION

The present disclosure relates to prosthetic heart valves. In oneembodiment, a prosthetic heart valve includes a stent having a proximalend, a distal end, an expanded condition and a collapsed condition. Thestent includes a plurality of distal cells at the distal end, aplurality of proximal cells at the proximal end, a plurality of supportstruts coupling the proximal cells to the distal cells, and at least onesupport post connected to a multiplicity of the proximal cells. Theproximal cells are longitudinally spaced apart from the distal cells. Avalve structure is connected to the at least one support post.

In another embodiment, a prosthetic heart valve includes a stent havinga proximal end, a distal end, an expanded condition and a collapsedcondition. The stent includes a plurality of distal cells at the distalend, a plurality of proximal cells at the proximal end, and at least onesupport post connected to a multiplicity of proximal cells. At least aportion of the proximal cells are directly connected to the distalcells. A valve structure is connected to the at least one support post.

In a further embodiment, a prosthetic heart valve includes a stenthaving a proximal end, a distal end, an expanded condition and acollapsed condition. The stent includes a plurality of cells at theproximal end, a plurality of support struts at the distal end, and atleast one support post connected to a multiplicity of the cells. Eachsupport strut has a first end connected to one of the cells and a freeend. A valve structure is connected to the at least one support post.

In yet another embodiment, a prosthetic heart valve includes a stenthaving a proximal end, a distal end, an expanded condition and acollapsed condition. The stent includes a plurality of cells, at leastone support post connected to a multiplicity of the cells, and areinforcement secured to the at least one support post. A valvestructure is connected to the at least one support post, thereinforcement being adapted to secure leaflets of the valve.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present invention will now be discussed withreference to the appended drawings. It is appreciated that thesedrawings depict only some embodiments of the invention and are thereforenot to be considered limiting of its scope.

FIG. 1 is a schematic longitudinal cross-section of an aortic root;

FIG. 2 is a developed view of a stent with a plurality of posts eachconnected to cells at two locations;

FIG. 3 is a developed view of a stent with a plurality of posts eachconnected to cells only at their proximal ends;

FIG. 4 is a developed view of a stent with a plurality of posts eachconnected to cells at their proximal ends and middle portions;

FIG. 5A is a developed view of a stent in an unexpanded condition with aplurality of posts each connected to cells at three locations;

FIG. 5B is a developed view of the stent of FIG. 5A in an expandedcondition;

FIG. 6A is a developed view of a stent in an unexpanded condition with aplurality of posts each connected to cells at three locations;

FIG. 6B is a developed view of the stent of FIG. 6A in an expandedcondition;

FIG. 7A is a partial perspective view of a stent showing a postconnected to cells at two locations;

FIG. 7B is a partial front elevational view of a stent showing a postconnected to cells at three locations;

FIG. 8A is a developed view of a stent in an unexpanded condition andincluding a plurality of posts and a plurality of spacersinterconnecting certain cells;

FIG. 8B is a front elevational view of the stent of FIG. 8A in anexpanded condition;

FIG. 9A is a developed view of a stent in an unexpanded conditionincluding support struts each having a curved middle portion;

FIG. 9B is a front elevational view of the stent of FIG. 9A in anexpanded condition;

FIG. 10A is a partial developed view of a stent in an unexpandedcondition and including a plurality of substantially rigid posts and aninterlocking feature;

FIG. 10B is a partial front elevational view of a stent in an expandedcondition and including a plurality of substantially rigid posts and aninterlocking feature;

FIG. 10C is a partial front elevational view of a stent in an expandedcondition and including a plurality of substantially rigid posts and aninterlocking feature;

FIG. 10D is front elevational view of a stent flared to anchor at asinotubular junction;

FIG. 10E is a front elevational view of a stent flared to anchor justabove the sinotubular junction and at the base of the aorta;

FIG. 10F is a front elevational view of a stent flared to anchor withinthe ascending aorta;

FIG. 11A is a developed view of a stent in an unexpanded condition andincluding a plurality of posts each connected at one end only to supportstruts;

FIG. 11B is a developed view of a stent in an unexpanded condition andincluding a plurality of posts and a plurality of support strut sets,each set being connected directly to a post and to cells adjacent thepost;

FIG. 11C is a developed view of a stent in an unexpanded condition andincluding a plurality of posts and a plurality of support strut sets,each support strut set being directly connected to a single post;

FIG. 11D is a developed view of a stent in an unexpanded condition andincluding a plurality of posts and a plurality of support struts, eachsupport strut being connected directly to a distal end of a single post;

FIG. 12A is a partial developed view of a stent in an unexpandedcondition and including at least one shortened post;

FIG. 12B is an enlarged view of an alternate post for incorporation intothe stent of FIG. 12A;

FIG. 12C is an enlarged view of an alternate post for incorporation intothe stent of FIG. 12A;

FIG. 13A is a partial developed view of a stent in an unexpandedcondition and including a post with a slidable portion;

FIG. 13B is a partial developed view of the stent of FIG. 13A in anexpanded condition;

FIG. 14A is a partial developed view of a stent in an unexpandedcondition with an elongated support post having a diamond-shapedcollapsible post structure;

FIG. 14B is a partial developed view of the stent of FIG. 14A in anexpanded condition;

FIG. 15A is a partial developed view of a stent in an unexpandedcondition with an elongated support post having a collapsible postfeature;

FIG. 15B is a partial developed view of the stent of FIG. 15A in anexpanded condition;

FIG. 16A is a partial developed view of a stent in an unexpandedcondition with an elongated support post having an hourglass-shapedcollapsible post feature;

FIG. 16B is a partial developed view of the stent of FIG. 16A in anexpanded condition;

FIG. 17A is a developed view of a stent in an unexpanded condition withsupport struts connected to a proximal cell spaced from the elongatedsupport post;

FIG. 17B is a developed view of a proximal portion of the stent of FIG.17A;

FIG. 18A is a developed view of a stent with a support strut connectedto a proximal cell located halfway between two elongated support posts;

FIG. 18B is a perspective view of the stent of FIG. 18A in an expandedcondition;

FIG. 18C is a perspective view of the stent of FIG. 18A in an unexpandedcondition;

FIG. 19 is a perspective view of the stent of FIG. 18A in an expandedcondition and subjected to a torsional force;

FIG. 20A is a perspective view of the stent of FIG. 18A in an expandedcondition and being twisted;

FIG. 20B is a perspective view of the stent of FIG. 18A in an expandedcondition and under longitudinal compression;

FIG. 21A is a side elevational view of a support strut with a taperedproximal end;

FIG. 21B is a side elevational view of a support strut with a uniformwidth;

FIG. 21C is a side elevational view of a support strut with a taperedmiddle portion;

FIG. 21D is a side elevational view of a support strut with an invertedC-shaped middle portion;

FIG. 21E is a side elevational view of a support strut with a C-shapedmiddle portion;

FIG. 21F is a side elevational view of a support strut with arectangular middle portion;

FIG. 21G is a side elevational view of a support strut with nestedlongitudinal cells;

FIG. 21H is a side elevational view of a support strut with a nestedcoil of cells;

FIG. 21I is a side elevational view of a support strut with asinusoidal-shaped middle portion;

FIG. 21J is a side elevational view of a pair of support struts withoffset sinusoidal-shaped middle portions;

FIG. 22 is a developed view of a stent with support struts cantileveredfrom proximal cells;

FIG. 23A is a partial perspective view of an embodiment of the stent ofFIG. 22 in an expanded condition with support struts having C-shapeddistal portions;

FIG. 23B is a partial perspective view of an embodiment of the stent ofFIG. 22 in an expanded condition with support struts having hook-shapeddistal portions;

FIG. 24 is a highly schematic, partial longitudinal cross-sectionshowing the stent of FIG. 23A positioned in an aortic annulus;

FIG. 25 is a highly schematic, partial longitudinal cross-sectionshowing the stent of FIG. 23B positioned in an aortic annulus;

FIG. 26 is a top partial view of a stent reinforced with two secondaryposts;

FIG. 27 is a partial developed view of a portion of a stent with a cuffand reinforced with two secondary posts;

FIG. 28A is a side elevational view of a secondary post with asubstantially circular cross-section;

FIG. 28B is a perspective view of the secondary post of FIG. 28A;

FIG. 28C is a side elevational view of a secondary post with asubstantially rectangular cross-section;

FIG. 28D is a perspective view of the secondary post of FIG. 28C;

FIG. 28E is a side elevational view of a secondary post with asubstantially triangular cross-section;

FIG. 28F is a perspective view of the secondary post of FIG. 28E;

FIG. 29A is a side elevational view of a secondary post with a hollowcore;

FIG. 29B is a side elevational view of a secondary post with a hollowcore and two different kinds of eyelets;

FIG. 30 is a side elevational view of a reinforcement for a stentincluding two columns connected by an arch;

FIG. 31A is a highly schematic, partial longitudinal cross-sectionshowing a reinforcement for use with a stent and adapted to be foldedonto itself;

FIG. 31B is a highly schematic top view of the reinforcement of FIG. 31Aoutlining the entire free end of a leaflet;

FIG. 32A is a perspective view of a prosthetic valve incorporating thereinforcement of FIG. 31A;

FIG. 32B is a perspective view of a prosthetic valve incorporating thereinforcement of FIG. 31A while the valve is subject to compression; and

FIG. 32C is a perspective view of a prosthetic valve incorporating thereinforcement of FIG. 31A while the valve is subject to compression.

DETAILED DESCRIPTION

As used herein, the term “proximal” refers to the end of a stent closestto the heart when placing the stent in a patient, whereas the term“distal” refers to the end of the stent farthest from the heart whenplacing the stent in a patient.

FIG. 1 illustrates the anatomy of an aortic root to aid in theunderstanding of how the stent/valve interacts with the aortic root.(FIG. 1 is from Reul, H., et al., “The geometry of the aortic root inhealth, at valve disease and after valve replacement,” Journal ofBiomechanics, Vol. 23, No. 2, 181-91, 1990). The aortic root is the partof the aorta attached to the heart. The aorta is the largest artery inthe body, which extends from the left ventricle of the heart down to theabdomen, where it branches off into two smaller arteries. The aortasupplies oxygenated blood to all parts of the body. The aortic rootcontains the aortic valve and gives rise to the coronary arteries, whichare the arteries that supply blood to the heart muscle. As shown in FIG.1, the aortic root 10 has several features, namely: a left ventricularoutflow tract (LVOT) 1; an annulus 2; a sinus 3; sinotubular junction(STJ) 4; and an ascending aorta 5. FIG. 1 further depicts severalgeometrical parameters of aortic root 10, to with: D_(O)=orificediameter; D_(A)=aortic diameter distal to the sinus 3; D_(B)=maximumprojected sinus diameter; L_(A)=length of the sinus 3; andL_(B)=distance between D_(O) and D_(B).

Flexibility of Stent Via Post Connections

In all the embodiments disclosed herein, the stents are part of aprosthetic heart valve. The stents have an expanded condition and acollapsed condition. In the expanded condition, at least a portion ofthe stent may have a substantially cylindrical shape. FIG. 2 depicts adeveloped view of stent 100 in an unexpanded condition, i.e., in a flat,rolled out condition as seen when laser cut from a tube. Stent 100generally includes one or more rows of distal cells 102, at least onesupport strut 104, one or more rows of proximal cells 106, at least oneelongated support post 108, and at least one post connection 110coupling a support post 108 to at least some of the proximal cells 106.One or more support struts 104 connect distal cells 102 to proximalcells 106. In some embodiments, three support struts 104 mayinterconnect proximal cells 106 and distal cells 102. Stent 100 maynonetheless include more or fewer support struts 104. Regardless of thespecific number of support struts 104, support struts 104 longitudinallyseparate proximal cells 106 from distal cells 102 and, therefore,proximal cells 106 are located proximally relative to distal cells 102.

Stent 100 or any other embodiment disclosed herein may be wholly orpartly formed of any biocompatible material, such as metals, syntheticpolymers, or biopolymers capable of functioning as a stent. Suitablebiopolymers include, but are not limited to, collagen, elastin, andmixtures or composites thereof. Suitable metals include, but are notlimited to, cobalt, titanium, nickel, chromium, stainless steel, andalloys thereof, including nitinol. Suitable synthetic polymers for useas a stent include, but are not limited to, thermoplastics, such aspolyolefins, polyesters, polyamides, polysulfones, acrylics,polyacrylonitriles, and polyaramides. For example, stent 100 may be madeof polyetheretherketone (PEEK).

Distal cells 102 are adapted to be positioned distally relative to sinus3 to anchor at or near the ascending aorta 5 and sinotubular junction 4.In certain embodiments, distal cells 102 may be arranged in longitudinalrows. In the embodiment shown in FIG. 2, stent 100 includes a single row114 of distal cells 102. The row 114 of distal cells 102 may be orientedsubstantially perpendicular to support struts 104. While FIG. 1 shows asingle row 114 of distal cells 102, stent 100 may include multiple rowsof distal cells 102.

Each distal cell 102 has a distal end 102 a, a proximal end 102 b, and amiddle portion 102 c between the distal end 102 a and the proximal end102 b. A cell connection 118 couples two adjacent distal cells 102. Asseen in FIG. 2, each cell connection 118 is positioned at a middleportion 102 c of a distal cell 102. Aside from the two adjacent distalcells 102, cell connection 118 is not coupled to any other distal cell102.

All distal cells 102 collectively have a first end portion 120 and asecond end portion 122. In the embodiment shown in FIG. 2, first endportion 120 is aligned with the proximal ends 102 b of the distal cells102, while the second end portion 122 is aligned with the distal ends102 a of the distal cells 102. Distal cells 102 are connected to supportstruts 104 at the first end portion 120. In some embodiments, supportstruts 104 are coupled to the proximal ends 102 b of some distal cells102.

Support struts 104 interconnect distal cells 102 and proximal cells 106.As discussed above, stent 100 may include one or more support struts104. As depicted in FIG. 2, stent 100 may include one support strut 104for every five proximal cells 106. Stent 100 may also include onesupport strut 104 for every seven distal cells 102. However, theseratios are not critical, and will depend on the size of proximal cells106 and distal cells 102, the desired stiffness of stent 100 and otherconsiderations.

Each support strut 104 has a first end portion 104 a, a second endportion 104 b, and a middle portion 104 c located between the first andsecond end portions. The first end portion 104 a of each support strut104 is connected to the proximal end 102 b of a distal cell 102. Thesecond end portion 104 b of each support strut 104 is connected to thedistal end 106 a of a proximal cell 106. Thus, a single support strut104 may couple a single distal cell 102 to a single proximal cell 106.

As shown in FIG. 2, the first and second end portions 104 a, 104 b ofeach support strut 104 may have straight or linear configurations, whilethe middle portion 104 c may have a non-linear configuration. In theembodiment depicted in FIG. 2, the middle portion 104 c of each supportstrut 104 has a sinusoidal or wave shape, but middle portions 102 c ofone or more support struts 104 may have other non-linear configurations.First and second end portions 104 a, 104 b of support struts 104 may beoriented substantially parallel to each other, and may be eitherlongitudinally aligned or not aligned with each other. For example,first and second end portions 104 a, 104 b of support struts 104 may belongitudinally aligned with each other, as seen in FIG. 2.Alternatively, portions 104 a and 104 b may be laterally offset fromeach other, for instance, with portion 104 b connected to the distal end106 a of a next adjacent proximal cell 106 to the left or right of theconnection depicted in FIG. 2.

As discussed above, at least one support strut 104 is connected to oneproximal cell 106. Each proximal cell 106 has a distal end 106 a, aproximal end 106 b and a middle portion 106 c between the distal end 106a and the proximal end 106 b. Together, proximal cells 106 areconfigured to impart radial force against the leaflets of a heart valve.Proximal cells 106 may be arranged in longitudinal rows. For example,stent 100 may include a first row 124 of proximal cells 106 positioneddistally of a second row 128 of proximal cells 106. At least one supportstrut 104 is connected to a proximal cell 106 located in the first row124.

A cell connection 130 couples two adjacent proximal cells 106 positionedin the same row. The proximal cells 106 in the first row 124 are joinedto the proximal cells 106 in the second row 128 by sharing one or morecommon cell legs.

The cells in the first row 124 and the cells in the second row 128 maynot form continuous chains of cells. That is, the chain of cells formingthe first row 124 and the chain of cells forming the second row 128 mayeach be disrupted by one or more elongated support posts 108. Supportposts 108 are intended to support the commissures along which the valveleaflets are joined to one another. In this embodiment, as in all of theembodiments described herein, the stent typically has three such supportposts 108, one for supporting each of the commissures of the aorticvalve. However, where the stent is intended for use in a prostheticvalve other than an aortic valve, the stent may include a greater orlesser number of support posts.

Stent 100 may include sets of proximal cells 106 between elongatedsupport posts 108. For example, as shown in FIG. 2, stent 100 mayinclude an elongated support post 108 between two sets of five proximalcells 106 in first row 124. However, the number of cells between supportposts 108 will depend on the size of proximal cells 106, the number ofcell rows and other such considerations. Support posts 108 may extendlongitudinally adjacent first cell row 124, second cell row 128 or bothcell rows. Similarly, support posts 108 may be connected to proximalcells in first cell row 124, second cell row 128 or both cell rows.

Stent 100 may include one support strut 104 for every set of proximalcells 106 located between two elongated support posts 108. For instance,stent 100 may have one support strut 104 for every set of five proximalcells 106 located between two elongated support posts 108. In thisembodiment, the second end portion 104 b of each support strut 104 isconnected to the proximal cell 106 located midway between two elongatedsupport posts 108. Support strut 104 is not connected to a proximal cell106 located adjacent to an elongated support post 108.

The support posts 108 may be connected to one or more proximal cells 106via post connections 110. Each elongated support post 108 has a proximalend 108 a, a distal end 108 b, and a middle 108 c. A plurality ofeyelets or apertures 132 are formed in each support post 108 and usedfor suturing the valve leaflets to stent 100. As seen in FIG. 2,apertures 132 may have different sizes, shapes and positions.

In the embodiment depicted in FIG. 2, post connections 110 are locatedat or near the middle 108 c of elongated support post 108 to allow forpost flexibility during valve cycling, thereby reducing dynamic loadingand the resulting in-leaflet stress. Specifically, the middle portions106 c of two proximal cells 106 located in the first row 124 areattached to opposite sides of the middle portion 108 c of each elongatedsupport post 108. Two proximal cells 106 arranged in the second row 128are attached near their middle portions 106 c to opposite sides of theproximal end 108 a of each elongate support post 108. Although FIG. 2shows post connections 110 at very specific locations, stent 100 mayinclude post connections 110 at other locations.

In operation, a user may place a stent 100 (or any other stent disclosedherein) using any conventional methods. For instance, the user may firstplace stent 100 in a crimped condition and then insert it into adelivery instrument or system. The delivery instrument may be advancedthrough the patient's vasculature or through a transapical procedureuntil stent 100 reaches the desired destination near the aortic valve.Subsequently, the user deploys and expands stent 100 at the target site.The structure of stent 100 described above provides very flexiblesupport posts 108 which reduce the maximum amount of stress at thecommissural interfaces on valve cycling. That is, since the distal endsof the support posts 108 are free from connections to the proximal cells106, these ends can move freely like a cantilever beam.

FIG. 3 shows another embodiment of a stent 200 with post connections 210coupling proximal cells 206 to elongated support posts 208 at differentlocations than for stent 100. Stent 200 is similar to stent 100 andgenerally includes distal cells 202, proximal cells 206, and supportstrut arrays 204 interconnecting the distal cells 202 and the proximalcells 206. In some embodiments, stent 200 may include a firstlongitudinal row 214 of distal cells 202, a second longitudinal row 216of distal cells 202, and a single longitudinal row 224 of proximal cells206.

Each distal cell 202 has a distal end 202 a, a proximal end 202 b, and amiddle portion 202 c between the distal end 202 a and the proximal end202 b. Cell connections 218 located at the middle portions 202 c of thedistal cells 202 in each row join two adjacent distal cells in that rowtogether. The distal cells 202 in the first row 214 are joined to thedistal cells 202 in the second row 216 by sharing one or more commoncell legs.

The proximal ends 202 b of every distal cell 202 located in the secondrow 216 may be connected to a support strut (205 or 207) of the supportstrut arrays 204. In the embodiment depicted in FIG. 3, stent 200includes three support strut arrays 204 each connected to eight distalcells 202 and six proximal cells 206. Each support strut array 204 mayalternatively be connected to more or fewer distal cells 202 andproximal cells 206. Regardless, each support strut array 204 includesone or more support struts (205 or 207) coupled to the proximal cells206 adjacent to an elongated support post 208 to halt any significantdistribution of the strains from post deflection to the remaining stentframe.

Each support strut array 204 may include two kinds of support struts,namely support struts 205 and support struts 207. In some embodiments,each support strut array 204 may include four support struts 205 and twosupport struts 207. Two support struts 207 may be positioned between twosets of two support struts 205. It is envisioned, however, that supportstrut arrays 204 may each include more or fewer support struts 205 and207.

Each support strut 205 has a first end portion 205 a, a second endportion 205 b, and a middle portion 205 c between the first and secondend portions. First end portion 205 a may be connected to a proximal end202 b of a distal cell 202 in the second row 216. Second end portion 205b may be connected to a distal end 206 a of a proximal cell 206. Middleportion 205 c has a straight or linear configuration and interconnectsfirst and second end portions 205 a, 205 b. The first end portion 205 aof each support strut 205 defines an oblique angle relative to middleportion 205 c. This oblique angle may vary from one support strut 205 toanother. The second end portion 205 b of each support strut 205 may alsodefine an oblique angle relative to middle portion 205 c. This obliqueangle may also vary from one support strut 205 to another.

Support struts 207 each have a first end portion 207 a, a second endportion 207 b, and a middle portion 207 c between the first and secondend portions. Each support strut 207 includes a bifurcated section 207 dextending from the middle portion 207 c to the first end portion 207 a.Bifurcated section 207 d of each support strut 207 includes two branches207 e, 207 f. Branches 207 e, 207 f are oriented substantially parallelto each other, except in a transition or angled portion 207 g of thebifurcated section 207 d in which the branches define an oblique anglewith respect to each other and to first and second portions 207 h and207 i. Each branch 207 e, 207 f includes a first portion 207 h, a secondportion 207 i, and the transition or angled portion 207 g positionedbetween the first and second portions. In the first portion 207 h of thebifurcated section 207 d, branches 207 e, 207 f are positioned fartherapart from each other than in the second portion 207 i.

Each branch 207 e, 207 f is connected to the proximal end 202 b of adistal cell 202 in the second row 216. Branches 207 e, 207 f of eachbifurcated section 207 d converge into a single support member 207 k atconverging point 207 m. Each single support member 207 k of supportstruts 207 may be connected to the distal end 206 a of a single proximalcell 206 adjacent a support post 208.

As discussed above, each support strut array 204 is connected to thedistal ends 206 a of a plurality of proximal cells 206. Specifically,support struts 207 are connected to proximal cells 206 positionedadjacent a support post 208, while support struts 205 are connected tothe proximal cells 206 which are not adjacent a support post 208.

Each proximal cell 206 has a distal end 206 a, proximal end 206 b and amiddle portion 206 c between the distal end 206 a and the proximal end206 b. The proximal cells 206 collectively define a first end 238 closerto support strut arrays 204 and a second end 240 farther from supportstrut arrays 204. Proximal cells 206 are arranged in a singlelongitudinal row. Cell connections 230 located at middle portions 206 cjoin adjacent proximal cells 206 together.

Some of the proximal cells 206 are connected to an elongated supportpost 208. As seen in FIG. 3, one or more elongated support posts 208 mayextend beyond the first end 238 collectively defined by all the proximalcells 206 but may not extend past the second end 240. Stent 200 mayhave, for example, one elongated post 208 for every six proximal cells206.

Each elongated support post 208 has a distal end 208 a, a proximal end208 b and a plurality of eyelets or apertures 232 for suturing the valveleaflets to the stent 200. As shown in FIG. 3, apertures 232 may extendfrom distal end 208 a to proximal end 208 b and may have differentshapes and sizes. In certain embodiments, apertures 232 may havesubstantially elliptical shapes.

Elongated support posts 208 are connected to proximal cells 206 by postconnections 210. In the embodiment shown in FIG. 3, post connections 210are located only at or near the proximal end 208 b of elongated supportpost 208 for allowing the elongated support post to deflect inwardly inthe direction indicated by arrow G under diastolic back-pressure.Although FIG. 3 shows post connections 210 at precise positions nearproximal ends 208 b, post connections 210 may be positioned closer orfarther from proximal ends 208 b to allow for more or less postflexibility. Each elongated support post 208 may be connected toproximal cells 206 through two post connections 210 located on oppositesides of the elongated support post.

FIG. 4 shows a stent 300 including distal cells 302, proximal cells 306,support strut arrays 304, elongated support posts 308 and postconnections 310 at two locations along each elongated support post 308.The positions of post connections 310 reduce post flexibility and thestrains experienced in post connections 310 as compared to the postconnections 210 in stent 200.

In the embodiment depicted in FIG. 4, stent 300 includes a single row314 of distal cells 302. Each distal cell 302 has a distal end 302 a, aproximal end 302 b and a middle portion 302 c between the proximal end302 b and the distal end 302 a. Cell connections 318 join adjacentdistal cells 302 at their middle portions 302 c.

Stent 300 may include one support strut array 304 for every eight distalcells 302. Each support strut array 304 may include four support struts305 joined to four distal cells 302. Each support strut array 304 maynonetheless include more or fewer support struts 305. In either event,support strut arrays 304 interconnect distal cells 302 and proximalcells 306.

Each support strut 305 has a first end portion 305 a, a second endportion 305 b, and a middle portion 305 c located between the first andsecond end portions. The first end portion 305 a of each support strut305 is connected to the proximal end 302 b of at least one distal cell302, whereas the second end portion 305 b of each support strut 305 isconnected to the distal end 306 a of at least one proximal cell 306.

The middle portion 305 c of each support strut 305 has a transitionsection 305 d connected to the first end portion 305 a. Transitionsection 305 d is oriented at an oblique angle relative to the middleportion 305 c. The middle portions 305 c of support struts 305 areoriented substantially parallel to each other except at the transitionsections 305 d. The first end portions 305 a of support struts 305 arealso oriented substantially parallel to each other.

The second end portion 305 b of each support strut 305 is connected tothe distal end 306 a of at least one proximal cell 306. Each second endportion 305 b has a substantially curved configuration or profile. Insome embodiments, each support strut array 304 may include four supportstruts 305 connected to the two proximal cells 306 adjacent to anelongated support post 308 and to the two next adjacent proximal cells.That is, two support struts 305 may be connected to a proximal cell 306adjacent to one side of elongated support post 308 and to the nextadjacent proximal cell, respectively, while another two support struts305 may be connected to a proximal cell 306 adjacent to the oppositeside of the same elongated support post 308 and to the next adjacentproximal cell, respectively.

Proximal cells 306 each have a distal end 306 a, a proximal end 306 band a middle portion 306 c between the distal end 306 a and the proximalend 306 b. Stent 300 may include a first row 324 of proximal cells 306and a second row 328 of proximal cells 306. First row 324 and second row326 of proximal cells 306 are oriented substantially parallel to eachother. First row 324 is located distally relative to second row 328. Allof the proximal cells 306 collectively define a first end 338 closer tothe support strut arrays 304 and a second end 340 farther from supportstrut arrays 304. The first end 338 of all the proximal cells 306 isdefined by the distal ends 306 a of the proximal cells located in firstrow 324, whereas the second end 340 is defined by the proximal ends 306b of the proximal cells 306 located in the second row 328.

A cell connection 330 joins the middle portions 306 c of adjacentproximal cells 306 in the first row 324. Other cell connections 330 jointhe middle portions 306 c of adjacent proximal cells 306 in the secondrow 328. The proximal cells 306 in the first row 324 are joined to theproximal cells in the second row 328 by sharing one or more common celllegs.

Elongated support posts 308 are connected to some proximal cells 306 bypost connections 310. In the embodiment depicted in FIG. 4, eachelongated support post 308 traverses the longitudinal length of theproximal cells 306 in the first row 324 and at least a portion of thelength of the proximal cells 306 in the second row 328. Each elongatedsupport post 308 has a distal end 308 a, a proximal end 308 b, and amiddle 308 c. In addition, each elongated support post 308 includes aplurality of eyelets or apertures 332 for suturing stent 300 to valveleaflets. Apertures 332 may have different shapes and sizes. At leastone elongated support post 308 may extend slightly beyond the first end338 collectively defined by all the proximal cells 306, as seen in FIG.4.

Post connections 310 may be positioned at two locations along eachelongated support post 308. As noted above, such positioning reducespost flexibility and the strains experienced in post connections 310.Two post connections 310 may be positioned on opposite sides of theproximal end 308 b of an elongated support post 308 and join theelongated support post 308 to the proximal ends 306 b of certainproximal cells 306 in the second row 328. Another two post connections310 may be located on opposite sides at or near the middle 308 c of anelongated support post 308 and join the middle of the support post tothe middle portions 306 c of certain proximal cells 306 in the first row324.

With reference to FIGS. 5A and 5B, a stent 400 includes a plurality ofcells 402, a plurality of support struts 404, one or more elongatedsupport posts 408 and post connections 410 coupling the elongated posts408 to cells 402. FIG. 5A shows stent 400 in a flat, rolled out,unexpanded condition, whereas FIG. 5B depicts stent 400 in a flat,rolled out, fully-expanded condition. Post connections 410 arepositioned at three locations along each elongated support post 408.Stent 400 further includes at least one runner or bar 450 extendinglongitudinally along cells 402. Bars 450 enable the length of stent 400to change substantially uniformly between the unexpanded and expandedconditions. The height and width of bars 450 may vary to accommodatevarious strength needs.

As discussed above, stent 400 includes a plurality of cells 402. Severalcell connections 430 join cells 402 to one another. Cells 402 may have adistal end 402 a, a proximal end 402 b, or both a distal end and aproximal end. All the cells 402 collectively define a first end 438 anda second end 440 and may be arranged in one or more longitudinal rows.For instance, stent 400 may include a first row 424, a second row 426and a third row 429 of cells 402 oriented substantially parallel to oneanother. The first row 424, second row 426 and third row 429 of cells402 are not continuous and may be disrupted by one or more elongatedsupport posts 408 interposed in the rows.

Each elongated support post 408 includes a distal end 408 a, a proximalend 408 b, a middle 408 c, and a plurality of eyelets or apertures 432for suturing stent 400 to the valve leaflets. The height H_(p) of eachelongated support post 408 defines the distance between distal end 408 aand proximal end 408 b. In the embodiment shown in FIG. 5A, allelongated support posts 408 are positioned between the first end 438 andthe second end 440 collectively defined by cells 402. The distal ends402 a of the cells 402 in the first row 424 extend distally beyond thedistal ends 408 a of each elongated support post 408 in the unexpandedcondition. The proximal ends of the cells 402 in the third row 429extend proximally beyond the proximal ends 408 b of each elongatedsupport post 408 in the unexpanded condition. As a result, cells 402 inrows 424 and 429 can be bent outwardly into a C-shape in the directionsindicated by arrows C so that stent 400 holds onto the stenotic nativevalve leaflets when the stent is positioned in the valve annulus 2.

Post connections 410 join elongated support posts 408 to cells 402. Asshown in FIG. 5B, stent 400 includes post connections 410 at threelocations along each elongated support post 408. First post connections410 are located on opposite sides of (or near) the proximal end 408 b ofelongated posts 408. Second post connections 410 are also positioned onopposite sides of (or near) the middle 408 c of elongated support posts408. Third post connections 410 are located on opposite sides ofelongated support posts 408 near distal ends 408 a. The post connections410 near distal ends 408 a may, for example, be positioned at aboutthree-quarters of height H_(p).

As discussed above, stent 400 may further include one or more bars 450for facilitating uniform expansion of the stent. Bars 450 join cells 402from first row 424 through the third row 429. As seen in FIG. 5B, eachbar 450 passes through cell connections 430 but does not extend past thefirst end 438 or the second end 440 collectively defined by cells 402.Bars 450 pass through the valleys formed between cells 402.

Stent 400 also includes one or more support struts 404 connected to aportion of the valleys formed between the distal ends 402 a of cells 402in the first row 424. Alternatively, support struts 404 may be connecteddirectly to the distal ends 402 a of cells 402. In some embodiments,support struts 404 may connect cells 402 to another group of cells (notshown).

FIG. 6A shows a stent 500 in a flat, rolled out, unexpanded state, whileFIG. 6B illustrates stent 500 in a flat, rolled out, expanded state.Stent 500 includes a plurality of cells 502, one or more elongatedsupport posts 508, and one or more bars 550 for enabling the length ofstent 500 to change substantially uniformly between the unexpanded andexpanded states. The structure and operation of stent 500 are similar tothe structure and operation of stent 400, but stent 500 includes postconnections 510 specifically located on opposite sides of the distalends 508 a of each elongated support post 508, rather than inward of thedistal ends as with stent 400. Stent 500 may further include one or moresupport struts 504 joining the distal ends 502 a of some cells 502 toanother set of cells (not shown).

Cells 502 of stent 500 are arranged in rows, namely first row 524 andsecond row 528. First row 524 and second row 528 of cells 502 areoriented substantially parallel to each other, as seen in FIG. 6A.Several cell connections 530 join cells 502 to one another. Each cellconnection 530 usually forms a valley or a peak between two cells 502.Bars 550 interconnect adjacent cells 502 positioned in different rows.In some embodiments, bars 550 may be connected to three cell connections530. Cells 502 collectively define a first end 538 and a second end 540.

Elongated support posts 508 are interposed between sets of cells 502 andtraverse both rows of cells. Each support post 508 has a distal end 508a, a proximal end 508 b, a middle 508 c, and a plurality of eyelets orapertures 532 for suturing stent 500 to the valve leaflets. The proximalend 508 b of each elongated post 508 does not extend beyond the secondend 540 collectively defined by all cells 402. The distal end 508 aextends slightly beyond the first end 538 collectively defined by allcells 502.

As seen in FIGS. 6A and 6B, stent 500 includes post connections 510joining each elongated support post 508 to adjacent cells 502 at threeparticular locations along the length of the support post. First postconnections 510 join opposite sides near the proximal end 508 b of anelongated support post 508 to the adjacent cells 502 located in thesecond row 528. Second post connections 510 join opposite sides of themiddle 508 c of each elongated support post 508 to the segments commonto the adjacent cells 502 in the first row 524 and the second row 528.Third post connections 510 join opposite sides of the distal end 508 aof an elongated support post 508 to the adjacent cells 502 located inthe first row 524. These last post connections 510 may be located at thevery end of the support post 508.

FIGS. 7A and 7B show similar stents 600A and 600B with different numbersof post connections 610. With reference to FIG. 7A, stent 600A includesdistal cells 602, proximal cells 606 and support struts 604, 605interconnecting the distal cells and proximal cells. Distal cells 602and proximal cells 606 are continuously connected around the entirecircumference of stent 600A, thereby allowing symmetric expansion andincreased radial force.

Distal cells 602 may be arranged in one or more longitudinal rows. Forexample, stent 600A may include only one row 614 of distal cells 602.Each distal cell 602 has a distal end 602 a and a proximal end 602 b,and may have a diamond shape upon expansion. Distal cells 602 areconnected to one another along row 614 via cell connections 618. Eachcell connection 618 is positioned at a valley formed between twoadjacent distal cells 602. The proximal ends 602 b of distal cells 602may be coupled in an alternating pattern to two different kinds ofsupport struts 604 and 605.

Support strut 605 has a distal end 605 a, a proximal end 605 b, and amiddle portion 605 c between the distal end and the proximal end. Thedistal end 605 a of each support strut 605 is connected to the proximalend 602 b of a distal cell 602, whereas the proximal end 605 b of eachsupport strut 605 is connected to the distal end 606 a of a proximalcell 606.

Support strut 604 has a distal end 604 a, a proximal end 604 b, and amiddle portion 604 c between the distal end and the proximal end. Thedistal end 604 a of each support strut 604 is connected to the proximalend 602 b of a distal cell 602. The proximal end 604 b of each supportstrut 604 is coupled to the distal end 606 a of a proximal cell 606. Themiddle portion 604 c of each support strut 604 includes a section 604 dfeaturing a non-linear shape. For example, non-linear section 604 d mayhave a sinusoidal or wave shape.

Proximal cells 606 are arranged in one or more longitudinal rows. Forinstance, stent 600A may include a first row 624 and a second row 626 ofproximal cells 606. First row 624 and second row 626 of proximal cells606 are oriented substantially parallel to each other.

Each proximal cell 606 may have an arrow shape in the expanded conditiondefined by a pair of peaks 606 a on opposite sides of a valley 606 b inone stent section, another pair of peaks 606 a on opposite sides of avalley 606 b in another stent section, and a pair of bars 650 connectingthe stent sections together.

Cell connections 630 interconnect proximal cells 606 positioned in thesame row. Each cell connection 630 may be positioned at a peak 606 ashared by two adjacent proximal cells 606 located in the same row.

Bars 650 not only define proximal cells 606, but also interconnectproximal cells 606 located in adjacent rows, thereby allowing uniformexpansion of proximal cells 606. Each bar 650 may be connected to one ormore cell connections 630.

Stent 600A further includes one or more elongated support posts 608.Each elongated support post 608 has a distal end 608 a, a proximal end608 b, and a middle 608 c, and includes one or more eyelets or apertures632 for suturing stent 600A to the valve leaflets.

Stent 600 may further include an interlocking feature 680 protrudingproximally from the proximal end 608 b of elongated support post 608.Interlocking feature 680 may have a substantially triangular shape andis configured to be attached to a delivery instrument or another cell.In one embodiment, interlocking feature 680 has a circular portion 682having an aperture 684.

Post connections 610 join each elongated support post 608 to proximalcells 606 located adjacent to the support post. In the embodiment shownin FIG. 7A, stent 600A includes two post connections 610 on oppositesides of the middle 608 c of each elongated support post 608 and anothertwo post connections 610 on opposite sides near the proximal end 608 bof each elongated support post 608. As a result, the distal ends 608 aof elongated support posts 608 are free and disconnected from anyproximal cell 606. This configuration provides stent 600A with a highdegree of flexibility and reduces the likelihood of distortion in thedistal portion of elongated support post 608 contorting the commissureregion and thus the valve function.

The proximal cells 606 adjacent to the distal end 608 a of elongatedsupport post 608 may be joined to each other by a particular kind ofcell connection 631. Cell connection 631 does not form a peak but rathera straight line in the annular direction of stent 600A. As seen in FIG.7A, cell connection 631 is not connected to elongated support post 608,thereby enabling the distal end 608 a of the stent post to flex.

Referring to FIG. 7B, stent 600B is substantially similar to stent 600A.However, stent 600B may include post connections 610 at three locationsalong elongated support post 608. For example, stent 600B may includepost connections 610 on opposite sides of the distal end 608 a of eachelongated support post 608, other post connections 610 on opposite sidesof the middle 608 c of each elongated support post 608, and other postconnections 610 on opposite sides near the proximal end 608 b of eachelongated support post 608. As discussed above, post connections 610join elongated support post 608 to proximal cells 606 adjacent toelongated support post 608.

In the embodiment shown in FIG. 7B, stent 600B only includes struts 605interconnecting the distal cells 602 and the proximal cells 606 and doesnot contain any struts 604 with a non-linear section 604 d. It isenvisioned, however, that stent 600B may include both struts 604 andstruts 605.

Stent 600B may include additional cell structural members 660 locateddistally of each elongated support post 608. Each cell structural member660 includes a first support member 662 and a second support member 664joined at a peak or distal end 666. First support member 662 and secondsupport member 664 together form a triangular structure connected toproximal cells 606 located on opposite sides of the distal end 608 a ofelongated support post 608. Each first support member 662 may beconnected to a distal end peak 606 a of a proximal cell 606 via a cellconnection 630. Each second support member 664 may be connected to astraight connection 631. In the embodiment shown in FIG. 7B, connection631 is not connected to proximal cells 606 or to an elongated supportpost 608, and is only coupled to the second support members 664 of eachcell structural member 660. As shown in FIG. 7B, the connection 631 andthe connected portions of support members 664 and struts 605 may befitted over an existing surgical or collapsible bioprosthetic valve V tolock the new valve in place. In lieu of elongated support post 608,stent 600A or stent 600B may include continuous proximal cells 606disjointed in the area where the leaflet commissures would be attached.

FIG. 8A shows a stent 700 in a flat, rolled out, unexpanded conditionand FIG. 8B shows stent 700 in an expanded condition. Stent 700generally includes distal cells 702, proximal cells 706, and a pluralityof support struts 704 interconnecting distal cells 702 and proximalcells 706.

Distal cells 702 are arranged in one or more longitudinal rows. In theembodiment shown in FIGS. 8A and 8B, stent 700 includes one longitudinalrow 714 of distal cells 702. Cell connections 718 join adjacent distalcells 702 arranged in the same row. Some adjacent distal cells 702,however, are connected by spacers 770. Spacers 770 allow symmetricexpansion of distal cells 714 and additional spacing for the coronaryarteries. Each spacer 770 may further include an interlocking feature,eyelets, radiopaque material, a landing-zone/latch-site for implantinganother similar expandable valve, or a combination thereof.

Although both spacers 770 and cell connections 718 connect adjacentdistal cells 702, spacers 770 separate adjacent distal cells 702 fartherfrom each other than cell connections 718. In some embodiments, threecell connections 718 may continuously couple four adjacent distal cells702 before a spacer 770 joins the next adjacent distal cell. Spacers 770may be arranged between cells 702 so as to be positioned in axialalignment with support posts 708.

Each distal cell 702 has a distal end 702 a and a proximal end 702 b.Upon expansion of stent 700, each distal cell 702 may have a diamondshape, as shown in FIG. 8B.

The proximal ends 702 b of each distal cell 702 may be connected to asupport strut 704. Each support strut 704 has a distal end 704 a andproximal end 704 b. The distal end 704 a of each support strut 704 iscoupled to a distal cell 702. The proximal end 704 b of each supportstrut 704 is connected to a proximal cell 706. Specifically, theproximal end 704 b of each support strut 704 is coupled to a cellconnection 730 located at a valley formed between two adjacent proximalcells 706.

As seen in FIG. 8B, the proximal end 704 b of each support strut 704 ispositioned proximally of the distal ends 708 a of elongated supportposts 708. As a consequence, the outward flaring of stent 700 in anexpanded condition can start proximally to the distal end of thecylindrical region (i.e., proximal cells 706).

Proximal cells 706 may be arranged in one or more longitudinal rows. Insome embodiments, stent 700 may include a first row 724 and a second row726 oriented substantially parallel to each other. Each proximal cell706 may feature an arrow shape in the expanded condition defined by adistal end or peak 706 a between two valleys 706 b and 706 c in onestent section, another peak 706 a between two valleys 706 b and 706 c inanother stent section, and a pair of bars 750 connecting the stentsections together.

Cell connections 730 couple adjacent proximal cells 706 arranged in thesame row. Each cell connection 730 may be located at a valley 706 b, 706c shared by two adjacent proximal cells 706 in the same row.

Bars 750 not only define proximal cells 706, but also connect proximalcells 706 located in adjacent rows. Each bar 750 may interconnectseveral cell connections 730 and permit uniform expansion of proximalcells 706. In some embodiments, each bar 750 passes through at leastthree cell connections 730 and is oriented substantially parallel to theelongated support posts 708.

Each elongated support post 708 of stent 700 has a distal end 708 a, aproximal end 708 b, and a middle 708 c. Proximal cells 706 may beconnected to an elongated support post 708 at three locations viaconnecting members 710. A first pair of connecting members 710 maycouple opposite sides of the distal end 708 a of an elongated supportpost 708 to two cell connections 730 attached to support struts 704. Asecond pair of connecting members 710 may couple opposite sides of themiddle 708 c of the elongated support post 708 to two cell connections730 located at the proximal ends 706 b, 706 c of two different proximalcells 706. A third pair of connecting members 710 may couple oppositesides near the proximal end 708 b of the elongated support post 708 totwo cell connections 730 located at the proximal ends 706 b, 706 c oftwo other proximal cells 706 located in the second row 726.

Stent 700 further includes an interlocking feature 780 protrudingproximally from the proximal end 708 b of one or more elongated supportposts 708. Interlocking feature 780 is configured to be attached to adelivery system and/or another valve. For instance, a delivery systemmay hold onto stent 700 through interlocking feature 780. In addition,another valve may be integrated with or attached to stent 700 viainterlocking feature 780. Interlocking feature 780 may have any suitableshape. In the illustrated embodiment, interlocking feature 780 has atriangular shape and a circular end portion 782 defining an aperture784. The stent 700 of a new valve may be fitted over an existingsurgical or collapsible bioprosthetic valve V to lock the new valve inplace.

FIG. 9A shows a stent 800 in a flat, rolled out, unexpanded conditionand FIG. 9B depicts stent 800 in an expanded condition. Stent 800 issubstantially similar to stent 700 described above and generallyincludes distal cells 802, proximal cells 806 and support strut arrays804 interconnecting distal cells 802 and proximal cells 806. Eachsupport strut array 804 includes two kinds of support struts, namely asupport strut 805 and two support struts 807.

Each distal cell 802 has a distal end 802 a and a proximal end 802 b.All distal cells 802 are arranged in one or more longitudinal rows 814.Cell connections 818 join adjacent distal cells 802 in the same row 814.In the embodiment shown in FIGS. 9A and 9B, stent 800 includes only onerow 814.

Some distal cells 802 are not connected to any support struts, whileother distal cells 802 are attached to a support strut 805 or 807. Thedistal cells 802 e that are not attached to any support strut 805 or 807allow further expansion of the longitudinal row 814 of distal cells. Insome embodiments, stent 800 includes three distal cells 802 connected tosupport struts 805, 807 for every distal cell 802 e that is not attachedto any support strut 805 or 807. Each distal cell 802 e that is notconnected to any support strut 805 or 807 may be positioned between aseries of distal cells 802 which is not connected to the support strut805 or 807. For example, in one embodiment, a single distal cell 802 ewhich is not connected to support struts 805 or 807 may be locatedbetween and adjacent two distal cells 802 attached to support struts807. In this embodiment, shown in FIG. 9A, each distal cell 802 coupledto a support strut 807 is located adjacent to a distal cell 802connected to a support strut 805.

As discussed above, each support strut array 804 includes two kinds ofsupport struts—a support strut 805 and a pair of support struts 807.Each support strut 805 has a distal end 805 a and a proximal end 805 band may be formed of a substantially flexible material. Support struts805 may have a linear configuration along their entire length. Thedistal end 805 a of each support strut 805 is connected to a distal cell802, while the proximal end 805 b of each support strut 805 is connectedto a proximal cell 806.

In some embodiments, support struts 805 may not be connected to alldistal cells 802. For example, support struts 805 may be coupled to oneof every four distal cells 802. Each support strut 805 may be positionedbetween two support struts 807.

Each support strut 807 has a distal end 807 a, a proximal end 807 b anda middle portion 807 c between the distal end and the proximal end. Thedistal end 807 a and the proximal end 807 b of each support strut 807have substantially linear or straight configurations. At least part ofmiddle portion 807 c of each support strut 807 has a curved profile orconfiguration. In some embodiments, middle portions 807 c have a C-shapeor an inverted C-shape.

The distal end 807 a of each support strut 807 may be connected to asingle distal cell 802. The proximal end 807 b of each support strut 807may be coupled to a proximal cell 806. In certain embodiments, supportstruts 807 may be connected only to the proximal cells 806 adjacent toan elongated support post 808. As shown in FIGS. 9A and 9B, one supportstrut 807 with a C-shaped middle portion 807 c may be connected to aproximal cell 806 located adjacent one side of an elongated support post808, while another support strut 807 with an inverted C-shaped middleportion 807 c may be connected to a proximal cell 806 positionedadjacent the opposite side of that elongated support post 808.

Each proximal cell 806 may have an inverted arrow shape upon expansiondefined by a pair of peaks 806 a on opposite sides of a valley 806 b inone stent section, another pair of peaks 806 a on opposite sides of avalley 806 b in another stent section, and a pair of bars 850 connectingthe stent sections together. Proximal cells 806 may be arranged in oneor more longitudinal rows. In some embodiments, stent 800 includesproximal cells 806 in a first row 824 and in a second row 826. Cellconnections 830 interconnect adjacent proximal cells 806 positioned inthe same row. Each cell connection 830 may be located at a peak 806 ashared by two adjacent proximal cells 806 located in the same row. Thevalleys 806 b at the proximal ends of the cells in the second row 824may also form the valleys 806 b at the distal ends of the adjacent cellsin the first row 826.

As seen in FIGS. 9A and 9B, all support struts 805 and 807 may beconnected to the peaks 806 a of the proximal cells 806 in first row 824.Alternatively, some or all support struts 805 and 807 may be attached tothe valleys 806 b of the proximal cells 806 in the first row 824.

Bars 850 not only define proximal cells 806, but also connect proximalcells 806 located in adjacent rows. Specifically, each bar 850 mayconnect several cell connections 830. In some embodiments, a bar 850 mayjoin at least three cell connections 830 located in different rows andtherefore permit uniform expansion of stent 800.

Some proximal cells 806 may be attached to an elongated support post808. Stent 800 may have one or more elongated support posts 808. In theembodiment shown in FIG. 8A, stent 800 has three such support posts 808.Each support post 808 has a distal end 808 a, a proximal end 808 b, anda middle 808 c. Post connections 810 attach some proximal cells 806 toopposite sides of the distal end 808 a, the proximal end 808 b and themiddle 808 c of the elongated support post 808.

Stent 800 may further include an interlocking feature 880 protrudingproximally from the proximal end 808 b of each elongated support post808. Interlocking feature 880 may be substantially similar to theinterlocking feature 780 of stent 700. The stent 800 of a new valve maybe fitted over an existing surgical or collapsible bioprosthetic valve Vto lock the new valve in place or may be used to lock the stent 800 atthe sinotubular junction 4.

FIGS. 10A, 10B, and 10C illustrate several embodiments of stents withsubstantially rigid posts or bars. These stents also have differentinterlocking features configured to be engaged to a delivery systemand/or another valve.

FIG. 10A depicts a portion of a stent 900 in a flat, rolled out,unexpanded condition. Stent 900 generally includes distal cells 902,proximal cells 906, and support struts 904 and 905 interconnectingdistal cells 902 and proximal cells 906. Some proximal cells 906 areattached to one or more elongated support posts 908 made wholly orpartly of a substantially solid or rigid material.

Proximal cells 902 are arranged in one or more longitudinal rows. Stent900 may include one longitudinal row 914 of proximal cells 902. Eachdistal cell 902 has a distal end 902 a, a proximal end 902 b, and amiddle portion 902 c between the distal end and the proximal end. Cellconnections 918 join adjacent distal cells 902 at their middle portions902 c.

At least one compartment 903 is interposed between the series ofproximal cells 902 in row 914. Preferably, stent 900 includes onecompartment 903 for each elongated support post 908. Each compartment903 includes a distal end 903 a, a proximal end 903 b, and a middleportion 903 c between the proximal end and the distal end. The distalend 903 a and the proximal end 903 b of each compartment 903 may havesubstantially linear or straight configurations oriented substantiallyparallel to each other at least in the unexpanded condition of stent900. Thus, in the unexpanded condition, compartment 903 has a generallyrectangular shape. Cell connections 918 may join opposite sides of themiddle portion 903 c of the compartment 903 to neighboring distal cells902.

The distal end 903 a of compartment 903 may include an interlockingfeature 980 configured to be attached to a delivery system and/oranother valve. Interlocking feature 980 protrudes proximally from thedistal end 903 a into the interior of compartment 903. In the embodimentshown in FIG. 10A, interlocking feature 980 includes rounded protrusion982 having an aperture 984.

As discussed above, stent 900 includes support struts 904 and supportstruts 905. At least some of support struts 904 and support struts 905may be made partially or entirely of a substantially rigid material tominimize a change in stent length, thereby reducing the risk of valvedamage during crimping of the prosthetic valve and providing a moreconsistent valve function in various implant diameters. Support struts904 interconnect the proximal end 902 b of a distal cell 902 to thedistal end 906 a of a proximal cell 906. In some embodiments, everydistal cell 902 may be connected to a proximal cell 906 via a supportstrut 904.

Support struts 905 couple the proximal end 903 b of compartment 903 tothe distal end 908 a of the elongated support post 908. In someembodiments, stent 900 may include two support struts 905 connecting asingle elongated support post 908 to a single compartment 903. Each ofthe support struts 905 may have a distal end 905 a and a proximal end905 b, and the struts may collectively form a triangular shape in theunexpanded condition of stent 900. The proximal ends 905 b of the twosupport struts 905 may be connected to spaced apart portions of the sameelongated support post 908. The distal ends 905 a of the two supportstruts 905 may converge for attachment to the proximal end 903 b ofcompartment 903 at a single point. In this arrangement, support struts905 define an oblique angle relative to one another.

All proximal cells 906 are arranged in one or more longitudinal rows andsome are attached to at least one elongated support post 908. Cellconnections 930 connect proximal cells 906 arranged on the same row,while bars or runners 950 join adjacent proximal cells 906 located indifferent rows.

As noted above, stent 900 includes one or more elongated support posts908. Each elongated support post 908 includes a distal end 908 a, aproximal end 908, and a middle 908 c. Post connections 910 join someproximal cells 906 to an elongated support post 908 at three locations.First post connections 910 connect two proximal cells 906 to oppositesides of the distal end 908 a of the elongated support post 908. Secondpost connections 910 connect two proximal cells 906 to opposite sides ofthe middle 908 c of the elongated support post 908. Third postconnections 910 coupled two proximal cells 906 to opposite sides nearthe proximal end 908 b of the elongated support post 908.

FIG. 10B illustrates a stent 1000A and FIG. 10C illustrates a stent1000B which are substantially similar to one another. Stents 1000A and1000B have interlocking features 1080 at different locations anddifferent kinds of elongated support posts.

As shown in FIG. 10B, stent 1000A includes at least one elongatedsupport post 1008, distal cells 1002 and proximal cells 1006 but doesnot include support struts. In other words, distal cells 1002 areconnected directly to proximal cells 1006.

Distal cells 1002 may be arranged in one or more longitudinal rows. Insome embodiments, stent 1000A may include a first row 1014, a second row1016 and a third row 1022 of distal cells 1002 oriented substantiallyparallel to each other. Each distal cell has a distal end or peak 1002a, a proximal end or valley 1002 b, and middle portions 1002 c. Thevalley 1002 b of a distal cell 1002 in one row may join the peak 1002 aof a distal cell in another row which is not adjacent to the one row.Upon expansion, each distal cell 1002 may have a diamond shape. Distalcells 1002 may be formed of a substantially flexible material andtherefore the cells can lengthen and expand to larger diameters.

Cell connections 1018 join adjacent distal cells 1002 in the same row.Distal cells 1002 in adjacent rows are joined by sharing common cellsegments. Stent 1000A further includes one or more cell spacers 1070each interconnecting two adjacent distal cells 1002 of the first row1014. Preferably, stent 1000A includes a cell spacer 1070 for eachelongated support post 1008. In the embodiment shown in FIG. 10B, a cellspacer 1070 may form a distal portion or end of a distal cell 1002 whichis located in the second row 1016 and connected to an elongated supportpost 1008. Cell spacer 1070 permits further expansion of stent 1000A,and may provide clearance between distal cells 1002 to accommodate thecoronary arteries.

As noted above, the proximal ends 1002 b of a distal cell 1002 in thesecond row 1016 are connected to the distal end 1008 a of an elongatedsupport post 1008. In addition, two distal cells 1002 in the third row1022 may be connected by their middle portions 1002 c to opposite sidesof the distal end 1008 a of the elongated support post 1008. Postconnections 1010 thus join the distal end 1008 a of elongated supportpost 1008 to both a distal cell 1002 in second row 1016 and to twodistal cells 1002 in third row 1022 positioned on opposite sides ofelongated support post 1008.

The distal cells 1002 in third row 1022 are directly connected to theproximal cells 1006 in a first row 1024 by a runner or bar 1050. Bar1050 is connected at one end to a cell connection 1018 in the third row1022 of distal cells 1002, and at the other end to cell connection 1030in the first row 1024 of proximal cells 1006.

Proximal cells 1006 may have a substantially inverted arrow shape uponexpansion defined by a pair of distal peaks 1006 a on opposite sides ofa valley 1006 b in one stent section, another pair of distal peaks 1006a on opposite sides of a valley 1006 b in another stent section, and apair of bars 1050 connecting the stent sections together. As seen inFIG. 10B, proximal cells 1006 may be arranged in longitudinal rows, suchas first row 1024 and second row 1026. Cell connections 1030 located atdistal peaks 1006 a interconnect adjacent proximal cells 1006 located inthe same row.

Bars 1050 not only define proximal cells 1006, but also interconnectproximal cells 1006 located in adjacent rows. In particular, each bar1050 may connect several cell connections 1030 located in differentrows. Bars 1050 may be formed of a substantially solid or rigidmaterial, thereby minimizing or limiting the change in stent lengthduring expansion of stent 1000A.

As previously noted, each elongated support post 1008 has a distal end1008 a. Additionally, each elongated stent post 1008 has a proximal end1008 b and a middle 1008 c, and may include a plurality of eyelets orapertures 1032. Elongated support posts 1008 may be formed of asubstantially solid or rigid material, thereby minimizing or limitingchanges in the stent length during expansion of stent 1000A.

In addition to the post connections 1010 described above, stent 1000Amay include post connections 1010 joining two proximal cells 1006 toopposite sides of the middle 1008 c of the elongated support post 1008.Other post connections 1010 may connect two proximal cells 1006 toopposite sides of the elongated support post 1008 near proximal end 1008b.

Stent 1000A further includes an interlocking feature 1080 protrudingproximally from the proximal end 1008 b of the elongated support post1008. As discussed below, interlocking feature 1080 may be positioned atother locations. Interlocking feature 1080 is configured to be attachedto a delivery system or another valve. In the embodiment shown in FIG.10B, interlocking feature 1080 has a triangular shape and a circularportion 1082 having an aperture 1084.

Referring to FIG. 10C, stent 1000B is substantially similar to stent1000A shown in FIG. 10B. However, stent 1000B includes an interlockingfeature 1080 protruding distally from spacer 1070. Moreover, stent 1000Bincludes an elongated support post 1008 having a different configurationthan the elongated support post of stent 1000A. The elongated supportpost 1008 of stent 1000B includes a post section 1008 d which has anarrower width relative to the rest of elongated support post 1008,thereby enhancing the flexibility of the elongated support post. Inaddition, the proximal end 1008 b of the elongated support post 1008shown in FIG. 10C does not include eyelets or apertures 1032, as do thedistal end 1008 a and middle 1008 c.

The stent designs depicted in FIGS. 10A, 10B, and 10C may be configuredto have shorter lengths than depicted in the figures to anchor atdifferent locations of the aortic root anatomy. For example, in FIG.10D, stent 1000C is substantially similar to stent 1000A of FIG. 10B buthas a suitable stent length L_(C) (with fewer rows of distal cells) anda flared configuration for anchoring at the sinotubular junction 4 ofthe aortic root 10 in the expanded condition. (See FIG. 1.) Withreference to FIG. 10E, stent 1000D is substantially similar to stent1000A shown in FIG. 10B. Stent 1000D nonetheless features a suitablestent length L_(D) and a flared configuration anchoring just above thesinotubular junction 4 and at the base of the aortic root 10 in theexpanded condition. Stent 1000D includes an interlocking feature 1080protruding proximally from each elongated support post 1008 and anotherinterlocking feature protruding distally from each spacer 1070.Referring to FIG. 10F, stent 1000E is substantially similar to stent1000D illustrated in FIG. 10E, but includes an additional row of distalcells, such as illustrated previously in FIG. 1000A. Stent 1000E maythus have a suitable stent length L_(E) and a flared configuration foranchoring within the ascending aorta.

FIGS. 11A-11D show several stent designs with different kinds of supportpost connections. These several types of support post connections reducethe amount of fatigue occurring at the joints connecting the supportposts to the remainder of the stent, and provide a desired amount ofpost flexibility.

Referring specifically to FIG. 11A, stent 1100 is similar to stent 200of FIG. 3. Stent 1100, however, includes support struts 1107 directlyconnected to the distal end 1108 a of the elongated support post 1108.Specifically, stent 1100 includes support strut arrays 1104interconnecting distal cells 1102 and elongated support posts 1108. Eachsupport strut array 1104 may include two support struts 1107. Althoughthe drawings show each support strut array 1104 as having two supportstruts 1107, support strut arrays 1104 may include more or fewer supportstruts 1107.

Each support strut 1107 has a distal end portion 1107 a, a proximal endportion 1107 b, and a middle portion 1107 c between the distal endportion and the proximal end portion. As seen in FIG. 11A, each supportstrut 1107 includes a bifurcated section 1170 d with a first branch 1107e and a second branch 1107 f. Each of the first branch 1107 e and thesecond branch 1107 f is connected to a single distal cell 1102.Accordingly, each support strut 1107 is attached to two distal cells1102. First and second branches 1107 e and 1107 f are orientedsubstantially parallel to each other except at a transition or angledregion 1107 g. At the transition region 1107 g, the first branch 1107 eand second branch 1107 f define an oblique angle relative to oneanother. In a portion of bifurcated section 1107 d located distally totransition region 1107 g, the first branch 1107 e and second branch 1107f are farther apart from each other than in the portion of bifurcatedsection 1107 d located proximally of transition region 1107 g.

The first branch 1107 e and second branch 1107 f converge into a singlesupport member 1107 k at or near the proximal end portion 1107 b of eachsupport strut 1107. Each single support member 1107 k is coupled to thedistal end 1108 a of the elongated support post 1108. Single supportmembers 1107 k each have a folded configuration, such as a tightlyfolded C-shape. Post connections 1110 join two single support members1107 k to the opposite sides of the distal end 1108 a of the elongatedsupport post 1108. Other post connections 1110 couple two proximal cells1106 to opposite sides of the elongated support post 1108 near proximalend 1108 b.

With reference to FIG. 11B, stent 1200 is substantially similar to stent1100. Stent 1200 includes distal cells 1202, proximal cells 1206, atleast one elongated support post 1208 attached between the proximalcells 1206, and at least one support strut array 1204 coupling thedistal cells 1202 to both the elongated support posts 1208 and theproximal cells 1206. Preferably, there is a support strut array 1204 foreach elongated support post 1208.

Each support strut array 1204 is similar to support strut array 1104 ofstent 1100. For example, each support strut array 1204 includes one ormore support struts 1207 with a bifurcated section 1207 g and a singlesupport member 1207 k. In this embodiment, single support member 1207 kis not directly connected to an elongated support member 1208. Rather,each single support member 1207 k divides into two arms—a first arm 1207p and a second arm 1207 m. First arm 1207 p extends proximally fromsingle support member 1207 k and is directly connected to a proximalcell 1206 adjacent to elongated support post 1208. Second arm 1207 mextends distally from single support member 1207 k and may double backupon itself to form an inverted U-shape before directly connecting tothe distal end 1208 a of the elongated support post 1208.

With reference to FIG. 11C, stent 1300 is substantially similar to thestent 1100 shown in FIG. 11A. Stent 1300 includes distal cells 1302,proximal cells 1306, at least one elongated support post 1308 attachedbetween the proximal cells 1306, and at least one support strut array1304 connecting the distal cells 1302 to the elongated support post1308. Preferably, there is a support strut array 1304 for each elongatedsupport post 1308. Each support strut array 1304 includes one or moresupport struts 1307. In the embodiment illustrated in FIG. 11C, eachsupport strut array 1304 includes two support struts 1307. In any event,each support strut 1307 has a bifurcated section 1307 g connected todistal cells 1302 and a single support member 1307 k attached to thedistal end 1308 a of the elongated support post 1308. Bifurcated section1307 g of each support strut 1307 has two branches, each of whichconnects to a single distal cell 1302. Single support member 1307 kconnects directly to the distal end 1308 a of the elongated support post1308 and is substantially shorter in length than the bifurcated section1307 g. The single support members 1307 k of two support struts 1307 maybe connected to opposite sides of the distal end 1308 a of the elongatedsupport post 1308.

FIG. 11D illustrates a stent 1400 substantially similar to stent 100depicted in FIG. 2. Stent 1400, however, includes at least one supportstrut 1404 with its proximal end 1404 b connected to the distal end 1408a of an elongated support post 1408. Preferably, stent 1400 includes asupport strut 1404 for each elongated support post 1408. Each supportstrut 1404 has a distal end 1404 a, a proximal end 1404 b and a middleportion 1404 c between the distal end and the proximal end. The distalend 1404 a of each support strut 1404 is connected to a single distalcell 1402. The middle portion 1404 c of each support strut 1404 has asinusoidal or wave shape.

With reference to FIG. 12A, stent 1500 includes a support post 1508 witha shorter post length as compared to the support post lengths of thepreviously described stents. Shortened support post 1508 has a distalend 1508 a and a proximal end 1508 b and, during use, reduces the amountof space taken up by the stent and valve material when in the unexpandedcondition. The design of stent 1500 allows for a strong structuralanchoring of the valve leaflets V at the distal end 1508 a of theshortened support post 1508. As seen in FIG. 12A, leaflets V graduallytaper away from shortened support post 1508. Since leaflet V is notconnected all the way to the proximal end 1508 b of the post 1508, areduced amount of leaflet material engages stent 1500, permitting stent1500 to be crimped down to a smaller diameter.

Two post connections 1510 couple two proximal cells 1506 to oppositesides of the distal end 1508 a of the shortened support post 1508.Another post connection 1510 joins a single central point of theproximal end 1508 b of the shortened support post 1508 to two additionalproximal cells 1506. There is no stent material proximally of the postconnection 1510 at the proximal end 1508 b of shortened post 1508.Indeed, stent 1500 has a gap 1590 defined between the proximal cells1506 positioned proximally of the proximal end 1508 b of the shortenedsupport post 1508. Accordingly, stent 1500 has a less stiff cantileveredpost 1508 and can be flexible even though post 1508 is connected toproximal cells 1506 at both its distal end 1508 a and its proximal end1508 b.

Stent 1500 may alternatively incorporate a full-length or elongatedsupport post 1509 as shown in FIG. 12B. Elongated support post 1509 islonger and narrower than shortened support post 1508 and includesreduced width portion 1509 d. Reduced width portion 1509 d is locatednear the proximal end 1509 b of the elongated support post 1509 andallows stent 1500 to be more compactly crimped. The overall reducedwidth of elongated support post 1509 also allows a user to secure theknots connecting a valve to elongated support post 1509 away from thecells. In addition to the reduced width portion 1509 d, elongatedsupport post 1509 includes eyelets or apertures 1532 and a base portion1509 e. Eyelets 1532 extend from the distal end 1509 a of elongatedsupport post 1509 along the section located distally of the reducedwidth portion 1509 d. Reduced width portion 1509 d and base portion 1509e do not have eyelets 1532. Base portion 1509 e is wider than reducedwidth portion 1509 d and may have a rectangular or paddle shape. In use,base portion 1509 e may function as an interlocking feature configuredto be attached to a delivery system or another valve.

Referring to FIG. 12C, stent 1500 may alternatively incorporateelongated support post 1511, which is substantially similar to elongatedsupport post 1509. Elongated support post 1511 is narrower than both theshortened support post 1508 of FIG. 12A and the elongated support post1509 of FIG. 12B, thus enabling an even smaller overall diameter whencrimped. In addition, elongated support post 1511 has a reduced widthportion 1511 d, a base portion 1511 e and a plurality of merged eyelets1533. Merged eyelets 1533 constitute two eyelets 1532 as shown in FIG.12B merged together. Eyelets 1533 are larger than eyelets 1532 of FIG.12A, thus making elongated support post 1511 more flexible thanelongated support post 1509. Base portion 1511 e can function as aninterlocking feature configured to be attached to a delivery system oranother valve.

With reference to FIGS. 13A and 13B, a stent 1600 includes a pluralityof cells 1602 and an elongated support post 1608. Some of these cells1602 are connected to the elongated support post 1608 via postconnections 1610. One group of post connections 1610 couple two cells1602 to opposite sides of the distal end 1608 a of the elongated supportpost 1608. Another group of post connections 1610 join two other cells1602 to opposite sides of the proximal end 1608 b of the elongatedsupport post 1608.

Ordinarily, because of the fixed length of elongated support post 1608,the cells 1602 immediately adjacent to the support post would not beable to expand away from the support post to create a spacetherebetween. To overcome this, however, and provide for the fullexpansion of stent 1600, elongated support post 1608 may be providedwith a sliding mechanism 1660 that enables the length of the elongatedsupport post to shorten upon expansion of stent 1600. Sliding mechanism1660 includes a central longitudinal slot 1666 which extends distallyfrom the proximal end 1608 b of elongated support post 1608, and afinger 1670 adapted for sliding engagement in slot 1666. Figure 1670 isfixedly connected to a cross-member 1672 positioned proximally of theelongated support post 1608. A pair of concave indentations 1668 onopposite sides of longitudinal slot 1666 can be used to secure a ring,suture, clip, or other structure that may be used as a guide. Uponexpansion of stent 1600, finger 1670 is able to slide into slot 1666,thereby allowing elongated support post 1608 to shorten. As aconsequence, the cells 1602 immediately adjacent to elongated supportpost 1608 are able to expand away from the support post. Slidingmechanism 1660 also allows different amounts of post deflection duringuse of stent 1600 in a prosthetic valve. As seen in FIG. 13B, theleaflet attachments and contour V allow movement of elongated supportpost 1608 in an area that does not affect the leaflet.

FIG. 14A shows a stent 1700 in a flat, rolled out, unexpanded conditionand FIG. 14B illustrates stent 1700 in a flat, rolled out, expandedcondition. Stent 1700 is substantially similar to stent 1600 but doesnot include a sliding mechanism. Instead, stent 1700 includes anelongated support post 1708 having a collapsible feature 1760 whichenables the length of the support post to shorten upon expansion of thestent. As with previous embodiments, elongated support post 1708 has adistal end 1708 a, a proximal end 1708 b, and a middle 1708 c. Inaddition, elongated support post 1708 includes eyelets or apertures1732. As shown in FIG. 14B, since the leaflet attachments of valve Vonly need the eyelets 1732 positioned near the distal end 1708 a ofelongated support post 1708, collapsible feature 1760 may be locatedbetween the middle 1708 c and the proximal end 1708 b of the elongatedsupport post. Nevertheless, collapsible feature 1760 may be positionedat any suitable location along the length of elongated support post1708. Irrespective of its position, collapsible feature 1760 enableselongated support post 1708 to shorten axially during expansion of stent1700, as shown in FIGS. 14A and 14B.

Collapsible feature 1760 may have a first end 1760 a and a second end1760 b. The first end 1760 a of the collapsible feature 1760 may beconnected to a portion of the elongated support post 1708 close to itsmiddle 1708 c, while the second end 1760 b of the collapsible featuremay be connected to a portion of the elongated support post 1708 nearits proximal end 1708 b. Collapsible feature 1760 may have a pluralityof legs 1764 arranged substantially in a diamond shape between its firstend 1760 a and its second end 1760 b, with a central opening 1762defined in the interior of legs 1764. Legs 1764 may be formed from aflexible or bendable material that can readily deform upon the expansionor crimping of stent 1700. The central opening 1762 allows collapsiblefeature 1760 to collapse when stent 1700 expands or to expand when stent1700 is collapsed. Consequently, elongated support post 1708 maylengthen or shorten as stent 1700 expands or collapses.

Referring to FIGS. 15A and 15B, stent 1800 is substantially similar tostent 1700 but includes a different kind of collapsible post structure.Stent 1800 includes cells 1802 and an elongated support post 1808 with acollapsible feature 1860. Elongated support post 1808 has a distal end1808 a, a proximal end 1808 b and a middle 1808 c between the distal endand the proximal end. Collapsible feature 1860 may be located betweenthe middle 1808 c and the proximal end 1808 b of the elongated supportpost 1808 and may include a first collapsible member 1862 having aserpentine or sinusoidal shape and a second collapsible member 1864having a similar serpentine or sinusoidal shape, with a central opening1866 defined between them. As shown in FIGS. 15A and 15B, collapsiblemembers 1862 and 1864 are flexible and therefore can freely move betweenan expanded condition and a collapsed condition. Central opening 1866facilitates the movement of collapsible members 1862 and 1864 betweenthe expanded and the collapsed conditions. Collapsible members 1862 and1864 allow elongated support post 1808 to shorten upon expansion ofstent 1800. In operation, collapsible feature 1860 axially extends whenstent 1800 is collapsed to a smaller diameter, and axially shortens whenstent 1800 is expanded to a larger diameter.

With reference to FIGS. 16A and 16B, stent 1900 is substantially similarto stent 1800 shown in FIGS. 15A and 15B, but includes a different kindof collapsible post structure. Stent 1900 includes cells 1902 and anelongated support post 1908 with a collapsible feature 1960. Elongatedsupport post 1908 has a distal end 1908 a, a proximal end 1908 b, and amiddle 1908 c between the distal end and the proximal end. Thecollapsible feature 1960 may be located between the middle 1908 c andthe proximal end 1908 b of the elongated support post 1908. Collapsiblefeature 1960 may include a first collapsible member 1962 and a secondcollapsible member 1964, with a central opening 1966 defined betweenthem. Collapsible members 1962 and 1964 are flexible and together maydefine an hourglass shape. Collapsible feature 1960 may move between alengthened condition (FIG. 16A) with stent 1900 in an unexpanded state,and a shortened condition (FIG. 16B) with stent 1900 in an expandedstate, allowing the elongated support post 1908 to change its lengthwhen a stent 1900 is expanded or crimped.

Flexibility of Stent Via Support Strut Connections

The support strut location and type is another primary design parameterthat can change the amount of flexibility of the support post. As thesupport strut is connected farther from the support post, it allows theload from the commissural region during back-pressure to be distributedalong the stent body gradually, instead of abruptly at the commissuresand struts connected to the stent. This not only decreases the dynamicloading on the valve leaflets, but also reduces strain on the stent. Thehighest dynamic loads are experienced in the embodiments in which thesupport struts are connected directly to the support posts (e.g., FIGS.11A-11D). Embodiments with support strut connections adjacent to thesupport posts (e.g., FIGS. 3 and 4) experience slightly less dynamicloads, while embodiments with support strut connections located fartherfrom the support posts (e.g., FIGS. 17A and 17B) experience even lessdynamic loads. Embodiments with support strut connections locatedhalfway between two adjacent support posts (e.g., FIGS. 5A, 5B and 18A,18B, and 18C) experience the least dynamic loads.

FIG. 17A shows a stent 2000 in a flat, rolled out, unexpanded conditionand FIG. 17B shows a proximal portion of stent 2000 in a flat, rolledout, fully-expanded condition. Stent 2000 generally includes a distalsinusoidal or serpentine pattern of half-cells 2002, proximal cells2006, support struts 2004 interconnecting distal half-cells 2002 andproximal cells 2006, and elongated support posts 2008 attached to someproximal cells 2006. Stent 2000 may include only half-cells 2002 (notcomplete cells) to reduce its overall length due to the possibility ofaortic arch bend constraints.

Each support strut 2004 has a distal end 2004 a connected to a distalhalf-cell 2002, a proximal end 2004 b attached to a proximal cell 2006,and a middle portion 2004 c between the distal end and the proximal end.The middle portion 2004 c of each support strut 2004 may have aserpentine or sinusoidal shape, as shown in FIG. 17A.

Proximal cells 2006 may be arranged in one or more rows. In theillustrated embodiment, stent 2000 includes a first row 2024 of proximalcells 2006 and a second row 2026 of proximal cells. Some proximal cells2006 in the first row 2024 and the second row 2026 are attached to anelongated support post 2008. The first row 2024 includes certainproximal cells 2006 which are joined to support struts 2004. Theproximal end 2004 b of each support strut 2004 is connected to aproximal cell 2006 f located one cell beyond the proximal cell 2006adjacent to the elongated support post 2008.

A plurality of cell connections 2030 may join adjacent proximal cells2006 in the same row. Proximal cells 2006 in different rows may bejoined by sharing common cell segments. Cell connections 2030 may bepositioned at the distal end of a proximal cell 2006 in the second row2026, which is coextensive with a middle portion of an adjacent proximalcell located in the first row 2024. Cell connections 2030 may also bepositioned at the proximal end of a proximal cell 2006 in the first row2024, which is coextensive with the middle portion of an adjacentproximal cell 2006 in the second row 2026. Some proximal cells 2006 inthe second row 2026 may be discontinuous in their middle portions, suchas through a disconnection or break 2090 at a cell connection 2030, toallow cell expansion in a different way as compared to previousembodiments.

Synergistic Physiological Stent Behavior Via Post Connections

The configuration and connections of the support struts may have aneffect on the annulus portion (i.e., proximal cells) of the stent andtherefore the valve function. For instance, the annulus section canfunction virtually independently in the torsional degree-of-freedom whenthe heart twists relative to the aorta during beating if the supportstruts are designed and connected to the cells as shown in FIGS. 18A,18B and 18C.

FIGS. 18A, 18B, and 18C show a stent 2100 which is substantially similarto stent 100 shown in FIG. 2. Stent 2100 includes support struts 2104connected to proximal cells 2106 located midway between two elongatedsupport posts 2108. FIG. 18A illustrates stent 2100 in a flat, rolledout, unexpanded condition; FIG. 18B shows stent 2100 perspectively in afully expanded and deployed condition; and FIG. 18C depicts stent 2100perspectively in an unexpanded condition. Stent 2100 generally includesdistal cells 2102, proximal cells 2106, support struts 2104interconnecting distal cells 2102 and proximal cells 2106, and elongatedsupport posts 2108 attached to some proximal cells 2108.

Each support strut 2104 has a distal end 2104 a, a proximal end 2104 band a middle portion 2104 c between the distal end and the proximal end.The distal end 2104 a of each support strut 2104 is connected to adistal cell 2102. The proximal end 2104 b of each support strut 2104 isconnected to a proximal cell 2106. Specifically, each support strut 2104is connected to a proximal cell 2106 f located midway between twoelongated support posts 2108 in order to increase flexibility andminimize the dynamic loads exerted on the elongated support posts. Stent2100 may include at least three support struts 2104 connected to threeproximal cells 2106 f, as seen in FIGS. 18A, 18B and 18C, for providinga stable connection of the aorta portion to the annulus portion whileproviding the greatest amount of stent frame flexibility. Preferably,stent 2100 has the same number of support struts 2104 as elongatedsupport posts 2108.

FIG. 18B illustrates stent 2100 in a substantially straightconfiguration as if the heart is not twisting during beating relative tothe aorta, and the aortic arch bend is not an issue. FIG. 19 depicts thesame stent 2100 with the valve section (i.e., proximal cells 2106)operating relatively free of adverse contortion from the twisting of theheart while still not allowing the stent to migrate.

Additional physiological concerns may arise due to translational(shortening or lengthening) motion and the bending and straightening ofthe ascending aorta. As seen in FIGS. 20A and 20B, however, the type andlocations of the support struts 2104 of stent 2100 also aid inmaintaining proper physiological motion, reduce leaflet stress, improverelatively independent valve function, and reduce certain stent strains,all while maintaining the necessary valve anchoring. FIG. 20Aillustrates the ability of stent 2100 to conform to an aortic arch bendwith little effect on its valve-functioning part (i.e., proximal cells2106). FIG. 20B shows stent 2100 with the valve section (i.e., proximalcells 2106) functioning relatively free of adverse contortion fromshortening and lengthening motions of the relative anatomicalstructures.

Any of the presently disclosed embodiments of stent may includedifferent kinds of support struts depending on the desired postflexibility and anatomical conformance. See e.g., FIGS. 21A-21J. Each ofthe support struts illustrated in FIGS. 21A-21J has its own directionaladvantage. The flexibility the illustrated support struts aids in theability to deliver the valve around tortuous vascular anatomy and theaortic arch when collapsed.

FIG. 21A shows a support strut 2204A with a tapered proximal portion2204 t. FIG. 21B illustrates a support strut 2204B featuring a uniformdiameter or cross-section along its entire length. FIG. 21C depicts asupport strut 2204C with a tapered middle portion 2204 k. The supportstruts shown in FIGS. 21A, 21B, and 21C can bend and twist but cannotelongate.

FIG. 21D shows a support strut 2204D with a bent middle portion 2204 m.Middle portion 2204 m has a generally rectangular inverted C-shape withthree sides 2204 n and two corners 2204 o. Two sides 2204 n may beoriented substantially parallel to each other and substantiallyorthogonal to the remainder of strut 2204D, while the third sideinterconnecting the first two sides may be substantially parallel to theremainder of strut 2204D. Corners 2204 o interconnect the differentsides 2204 n and may be rounded. FIG. 21E illustrates a support strut2204E with a bent middle portion 2204 r. Middle portion 2204 r has agenerally rounded C-shaped profile. The support struts shown in FIGS.21D and 21E can bend and twist more than the struts of FIGS. 21A, 21B,and 21C, and can also shorten and elongate.

FIG. 21F shows a support strut 2204F with a rectangular middle portion2204 s. Middle portion 2204 s has a substantially rectangular shape andincludes four sides 2204 u connected to one another and collectivelydefining a central opening 2204 q. Support strut 2204F can bend, twist,shorten and elongate. The middle portion 2204 s provides redundantsupport to strut 2204F.

FIG. 21G shows a support strut 2204G with nested longitudinal cells 2204v in its middle portion and extending toward the proximal end of thesupport strut. Support strut 2204G can bend more easily than previousembodiments, but may have limited elongation capabilities. FIG. 21Hshows a support strut 2204H with a nested coil of cells 2204 x in itsmiddle portion. The nested coil of cells 2204 x can bend, twist andelongate via a circular nested mechanism.

FIG. 21I illustrates a support strut 2204I with a single serpentine orsinusoidal link 2204 y in its middle portion. Support strut 2204I canbend and twist and can also elongate more easily than previousembodiments. FIG. 21J shows a pair of support struts 2204J each havingserpentine-shaped links 2204 z in their middle portions. Theserpentine-shaped link 2204 z of one support strut 2204J is offset tothe left (or away from the other support strut 2204J), while theserpentine-shaped link 2204 z of the other support strut 2204J is offsetto the right (or away from the other support strut 2204J).

Flexibility of Stent Post and Anatomical Conformance Via IndependentPost Connections

Stents may not only have both an annular portion (i.e., proximal cells)and an aortic/sinotubular junction portion (i.e., distal cells), but mayalternatively have independently contouring support struts to conform tothe differences in anatomy/physiology around the circumference of theaortic root. This can help to anchor the valve with the least amount ofunwanted load transfer to the support post area of the valve.

Referring to FIG. 22, stent 2300 generally includes proximal cells 2306,elongated support posts 2308, and a plurality of support struts 2304each connected at a proximal end 2304 b to a proximal cell 2306, andextending distally therefrom in a cantilevered fashion to a free distalend 2304 a. Each elongated support post 2308 is attached at its distalend 2308 a, proximal end 2308 b and middle 2308 c to some of cells 2306.Each support strut 2304 is free to move independently and to contour tothe anatomy/physiology of the patient's aortic root. Since the supportstruts 2304 can be independently contoured to the anatomy, the distalend 2304 a of each support strut 2304 can anchor in the aorta, aboveand/or below the sinotubular junction, around the free edge of the valveleaflets. Stent 2300 does not have distal cells. The absence of distalcells provides stent 2300 with greater post flexibility while stillproviding additional anchoring capabilities. Although FIG. 22 showssupport struts 2304 with a substantially straight configuration, thispreferably is prior to final processing to provide the support strutswith desired configurations.

FIGS. 23A and 23B show some different configurations which cantileveredsupport struts 2304 may have. In the interest of simplicity, FIGS. 23Aand 23B show the valve portion of the stent (e.g., proximal cells andelongated support posts) as a ring. This ring, however, does not reallyexist and merely illustrates that the support struts 2304 are held inplace by other structures of the stent. In the embodiments shown inFIGS. 23A and 23B, each support strut 2304 has a proximal end 2304 battached to proximal cell or an elongated support post (not shown) and afree distal end 2304 a. However, the distal ends 2304 a of the supportstruts 2304 of these two embodiments have different configurations.

In the embodiment shown in FIG. 23A, each support strut 2304 has acurved profile 2304 c near its distal end 2304 a. The curved profiles2304 c initially bend outwardly or away from one another to anchor justdistally of the sinotubular junction, but, closer to the distal ends2304 a, the curved profiles 2304 c bend inwardly or toward one anotherto reduce the possibility of aortic perforation or dissection by asupport strut 2304.

In FIG. 23B, the stent includes support struts 2304 designed to seataround and/or just proximal to the sinotubular junction in the distalportion of the sinus. The support struts 2304 of the embodiment shown inFIG. 23B also have a curved profile 2304 d near their distal ends 2304a. This curved profile 2304 d initially bends outwardly (or away fromone another) and then proximally, thereby forming a hook, but, closer tothe distal ends 2304 a, the curved profile 2304 d bends distally.

A single stent 2300 may have the support struts shown in both FIGS. 23Aand 23B. Additionally, support struts 2304 may be used to latch ontofeatures of previously implanted prosthetic valves, such as the spacer770 shown in FIGS. 8A and 8B.

FIG. 24 shows how the curved profile or anchoring feature 2304 c of thesupport strut 2304 shown in FIG. 23A can be contoured to fasten abovethe stenotic leaflets or prosthetic valve 6 and below the sinotubularjunction 4. The curved profile 2304 c of stent 2300 bluntly anchors tothe aortic root to minimize migration. The remaining part of stent 2300is anchored to a stenotic leaflet or prosthetic valve 6 and the annulus2 of the aortic root. In addition, a fabric and/or tissue layer T may beattached to the interior of the stent 2300, and a leaflet L may beattached to the tissue layer. The tissue layer T and leaflet L functionas a valve to prevent backflow, as indicated by arrow F, when in theclosed condition.

FIG. 25 shows how the curved profile 2304 d of the support strut 2304shown in FIG. 23B can be contoured to fasten above the stenotic leafletsor prosthetic valve 6 and below the sinotubular junction 4. The curvedprofile or anchoring feature 2304 d of stent 2300 anchors to the aorticroot, thereby minimizing migration. As discussed above, a fabric ortissue layer T may be attached to the interior of stent 2300, and aleaflet L may be attached to the tissue layer. The tissue layer T andthe leaflet L act as a valve, preventing or least hindering backflowwhen in the closed condition, as indicated by arrow F.

Leaflet Reinforcement to Reduce Stress at Commissures

As the flexibility of the post and/or stent frame decreases (due to, forexample, more connections along the support post), it may be necessaryto distribute the greater stress at the commissures. The stress may bedistributed to the commissures by, for example, reinforcements at thesupport posts. The reinforcements may also reduce the possibility of theleaflets hitting the stent frame.

FIG. 26 is a top view of a stent 2500 having a support post 2508 andsecondary posts 2510 used for reinforcement. Secondary posts 2510 may bemade from a material, such as stainless steel, which is more resistantto fatigue than Nitinol, from which stent 2500 may be made. Support post2508 has at least two eyelets or apertures 2532. Each secondary post2512 has two eyelets 2512 oriented substantially perpendicular to eachother in a crossing pattern. Secondary posts 2510 may be attached tosupport post 2508 using sutures S. One suture S passes through oneeyelet 2532 of support post 2508 and through a corresponding eyelet 2512of one secondary post 2510, thereby attaching that secondary post to thesupport post. Another suture S passes through another eyelet 2532 ofsupport post 2508 and through a corresponding eyelet 2512 of the othersecondary post 2510, thereby attaching that secondary post to thesupport post. Thus, both secondary posts 2510 are attached to supportpost 2508 with sutures S.

The secondary posts 2510 may also be attached to each other by passing asuture S through an eyelet 2512 of one secondary post 2510 and anothereyelet 2512 of the other secondary post 2510. In the embodiment shown inFIG. 26, the secondary posts 2510 sandwich the tissue of the twoleaflets K. Leaflets K may be tissue, but this design lends itself topolymer dip coating onto secondary posts 2510 before attaching theresulting subassembly onto strut 2500 via large eyelets at the top andbottom of the support posts.

The foregoing reinforcement technique may also be used with stents whichdo not have support posts. FIG. 27 shows one-third of the side of astent 2600 that does not have support posts. Stent 2600 includes atleast two rows of cells 2606, and may include a first row 2622 and asecond row 2624 of cells 2606. Cell connections 2630 interconnectadjacent cells 2606 in the same row. Bars 2650 couple cells 2606positioned in adjacent rows and may be formed of a substantially rigidmaterial. A fabric or tissue cuff 2690 may be attached around theinterior or exterior of stent 2600 and cover almost the entirety of thecells 2606, leaving only open areas 2692 for the coronary arteries. Openareas 2692 expose only distal portions 2606 a of some cells 2606.Secondary posts 2610 may be sutured to the cuff 2690, to bars 2650and/or to the segments forming cells 2606.

FIGS. 28A-28F illustrate different reinforcements or secondary posts2710, 2720, and 2730, which may be attached as rigid structures to anysuitable stent as shown in FIG. 26. All secondary posts 2710, 2720, 2730may have eyelets 2732 along their length for receiving sutures. Eyelets2732 may also be positioned on multiple sides of each secondary post2710, 2720, 2730 to allow for multidirectional suturing. The eyelet 2732closest to the distal end 2702 of the secondary post 2710, 2720, or 2730may not be spaced apart from the adjacent eyelet 2732 as much as theother eyelets 2732 are spaced apart from each other. Further, the edgesof the eyelets 2732 and the edges of the secondary posts 2710, 2720 and2730 are preferably rounded to eliminate suture and leaflet abrasion.

Each secondary post 2710, 2720, 2730 may have a different shape orcross-section. For example, secondary post 2710 has a substantiallycircular cross-section, as seen in FIGS. 28A and 28B. Secondary post2720 may have a substantially rectangular shape or cross-section, asseen in FIGS. 28C and 28D. Secondary post 2730 may have a triangularshape or cross-section, as seen in FIGS. 28E and 28F.

FIGS. 29A and 29B show reinforcements or secondary posts 2810 and 2820adapted to be attached to a stent as shown in FIG. 26. Posts 2810 and2820 have a hollow core and may feature a smoothly curved or cylindricalshape. Post 2810 has eyelets 2812 along its length. Eyelets 2812 mayhave an oblong or elliptical shape. Post 2820 may have two differentkinds of eyelets 2822 and 2824. Eyelets 2822 are in the form ofalternating through-holes with a substantially oblong or ellipticalshape. A partial eyelet 2824 located near the distal end 2820 a of post2820 has a substantially circular shape to hold a suture.

FIG. 30 shows a reinforcement 2900 that may be attached to the stent, asshown in FIG. 26, in lieu of the secondary posts. Reinforcement 2900includes a first column 2910, a second column 2912, and an arch 2914interconnecting the first and second columns. First column 2910 has afirst end 2910 a and a second end 2910 b. Second column 2912 has a firstend 2912 a and a second end 2912 b. Arch 2914 connects the first end2910 a of the first column 2910 to the first end 2912 a of the secondcolumn 2912 and sets the width W between the first and second columns.The first column 2910 and the second column 2912 define a gap 2916between them. Gap 2916 has a width W and is dimensioned to receive thevalve leaflets K (FIG. 26). With leaflets K sandwiched between the firstcolumn 2910 and the second column 2912, arch 2914 absorbs the openingload of the leaflets instead of the sutures since columns 2910 and 2912may want to pull apart.

FIG. 31A shows a pliable reinforcement 3000 folded over a free edge of aleaflet and sutured to itself and to the stent frame or post. In someembodiments, reinforcement 3000 may be attached to a free edge of aleaflet at the commissure 9, but away from the belly region 8 of thevalve leaflet, as shown in FIG. 31A. Alternatively, reinforcement 3000may be attached to the entire sutured edge of the leaflet, which wouldresult in the shape seen in FIG. 31B.

Reinforcement 3000 includes a securing section 3004 and an optional flap3002 for additional suturing and securement to a support post. As seenin FIG. 31A, reinforcement 3000 is folded onto itself along a foldingline F_(L). In particular, a folding area 3008 is folded over a securingsection 3004 as indicated by arrow M to form a substantially V-shapedstructure. At this point, reinforcement 3000 partially wraps a free edgeof a valve leaflet. Sutures may be used to secure reinforcement 3000 ina folded condition. One or more sutures may pass over the free edge ofthe leaflet outside of reinforcement 3000 to secure the reinforcement3000 in a folded condition. In such case, the suture should be more than1 mm from the free edge of the leaflet. For thicker leaflets, it may benecessary to enlarge the folding area 3008 to allow the reinforcement3000 to wrap over the free edge of the leaflet. Folding area 3008defines cutout 3010 which may be substantially V-shaped for straddlingthe leaflets.

Securing section 3004 has a base 3006 aligned with an eyelet at theproximal end of a support post, and an angled side 3014 oriented at anoblique angle relative to folding line F_(L) and base 3006. Angled side3014 of securing section 3004 biases the valve opening away from asupport post. For instance, angled side 3014 may bias the valve openingabout 3 mm away from a support post.

As discussed above, reinforcement 3000 may optionally include a flap3002 which provides additional securement to the support post. Forexample, additional sutures may attach the flap 3002 to the supportpost. Flap 3002 may also protect moving leaflets from knots securing thereinforcement 3000 to the support post. The distance between the edge offlap 3002 and angled side 3014 along folding line F_(L) should besufficient to keep the leaflets from opening against the stent.Reinforcement 3000 may be attached to a stent S_(T) as shown in FIG.33A. Regardless of the manner in which stent S_(T) is deformed, as shownin FIGS. 33B and 33C, there is a low likelihood of the valve leafletabrading against the stent.

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims.

It will be appreciated that the various dependent claims and thefeatures set forth therein can be combined in different ways thanpresented in the initial claims. It will also be appreciated that thefeatures described in connection with individual embodiments may beshared with others of the described embodiments.

The invention claimed is:
 1. A prosthetic heart valve, comprising: astent having a proximal end, a distal end, an expanded condition and acollapsed condition, the stent including: a series of proximal cells atthe proximal end; a series of distal cells at the distal end, the distalcells being longitudinally spaced apart from the proximal cells; aplurality of support struts, each support strut having a first endconnected to the series of proximal cells and a second end connected tothe series of distal cells; and at least one support post connected to amultiplicity of the proximal cells, the multiplicity of proximal cellsbeing connected to the support post at three spaced positions along alength of the support post; and a valve structure connected to the atleast one support post.
 2. The prosthetic heart valve as claimed inclaim 1, wherein the three spaced positions include a proximal end ofthe support post, a distal end of the support post, and a positionintermediate the proximal and distal ends of the support post.
 3. Theprosthetic heart valve as claimed in claim 1, wherein the support posthas a first longitudinal side and a second longitudinal side and themultiplicity of proximal cells are connected to the support post atthree spaced positions along the first longitudinal side and at threespaced positions along the second longitudinal side.
 4. The prostheticheart valve as claimed in claim 3, wherein the three spaced positionsalong the first longitudinal side include a proximal end of the supportpost, a distal end of the support post, and a position intermediate theproximal and distal ends of the support post, and the three spacedpositions along the second longitudinal side include the proximal end ofthe support post, the distal end of the support post, and the positionintermediate the proximal and distal ends of the support post.
 5. Aprosthetic heart valve as claimed in claim 1, wherein a first proximalcell is connected to the support post at a first one of the spacedpositions, a second proximal cell different from the first proximal cellis connected to the support post at a second one of the spacedpositions, and a third proximal cell different from the first proximalcell and the second proximal cell is connected to the support post at athird one of the spaced positions.
 6. A prosthetic heart valve,comprising: a stent extending in a longitudinal direction between aproximal end and a distal end, the stent having an expanded conditionand a collapsed condition, the stent including: a series of proximalcells at the proximal end, the series of proximal cells including afirst annular row of cells extending around a circumference of the stentand a second annular row of cells extending around the circumference ofthe stent, each of the cells in the first annular row including at leastone bar oriented substantially parallel to the longitudinal direction inthe expanded condition of the stent; a series of distal cells at thedistal end, the distal cells being spaced apart in the longitudinaldirection from the proximal cells; a plurality of support struts, eachsupport strut having a first end connected to the series of proximalcells and a second end connected to the series of distal cells; and atleast one support post connected to a multiplicity of the proximalcells; and a valve structure connected to the at least one support post.7. The prosthetic heart valve as claimed in claim 6, wherein each of thecells in the second annular row is formed by a plurality of struts so asto have substantially a diamond shape with a first end pointing towardthe distal end of the stent and a second end pointing toward theproximal end of the stent.
 8. The prosthetic heart valve as claimed inclaim 7, wherein the series of proximal cells further includes a thirdannular row of cells extending around the circumference of the stent,each of the cells in the third annular row including at least one baroriented substantially parallel to the longitudinal direction.
 9. Theprosthetic heart valve as claimed in claim 6, wherein each of the cellsin the first annular row is formed by a plurality of struts includingfirst and second struts joined together to form a first joint pointingtoward the proximal end of the stent and third and fourth struts joinedtogether to form a second joint pointing toward the proximal end of thestent.
 10. The prosthetic heart valve as claimed in claim 6, whereineach of the cells in the second annular row includes at least one baroriented substantially parallel to the longitudinal direction, the barsin the first annular row being longitudinally aligned with the bars inthe second annular row.
 11. The prosthetic heart valve as claimed inclaim 6, wherein each of the cells in the first annular row includes aplurality of struts joined together to form a first annular series ofpeaks and a second annular series of peaks, the first annular series ofpeaks including peaks pointing toward the proximal end of the stentalternating with peaks pointing toward the distal end of the stent, andthe second annular series of peaks including peaks pointing toward theproximal end of the stent alternating with peaks pointing toward thedistal end of the stent, the first annular series being connected to thesecond annular series by a plurality of bars oriented substantiallyparallel to the longitudinal direction, each bar interconnecting peakspointing in the distal direction.
 12. A prosthetic heart valve,comprising: a stent extending in a longitudinal direction between aproximal end and a distal end, the stent having an expanded conditionand a collapsed condition, the stent including a series of proximalcells at the proximal end, a series of distal cells at the distal end,the distal cells being spaced apart in the longitudinal direction fromthe proximal cells; a plurality of support struts, each support struthaving a first end and a second end, each of the proximal cells beingconnected to the first end of one of the support struts and each of thedistal cells being connected to the second end of one of the supportstruts; and at least one support post connected to a multiplicity of theproximal cells; and a valve structure connected to the at least onesupport post.
 13. The prosthetic heart valve as claimed in claim 12,wherein each support strut extends substantially parallel to thelongitudinal direction in the expanded condition of the stent.
 14. Theprosthetic heart valve as claimed in claim 12, wherein the stentincludes a greater number of distal cells than proximal cells.
 15. Theprosthetic heart valve as claimed in claim 14, wherein a group of thesupport struts is bifurcated so that the first end of the support strutsin the group of support struts is connected to one of the proximal cellsand the second end of the support struts in the group of support strutsis connected to a plurality of distal cells.